Book 15 activities
Try it at home: 150 science activities from Book 15
Every question in A Million Whys Book 15, The Robot Expedition, ends with a "Think like a scientist" idea. Here they are in one place. Each one links to its question page, with the video and the full answer.
Expedition 1: Robot Basics (25)
1. Why Do We Call a Machine a Robot?
Pick three machines at home, like a toaster, a robot vacuum, and a fan. For each, ask: does it sense? Does it decide? Does it act? Which ones pass all three questions?
Do this with a grown-up2. Why Isn't a Remote-Control Car a Robot?
If you have a remote-control toy, drive it around a chair. Who is doing the sensing and deciding? What would the car need to do it without you? If you do not have one, act it out with a friend.
3. Why Is a Toaster Not a Robot but a Robot Vacuum Is?
Make a chart with two columns for a toaster and a robot vacuum: “What does it sense?” and “What does it decide?” Fill in as many boxes as you can.
Do this with a grown-up4. Where Does the Word Robot Come From?
Ask your family about words that came from other languages, like pizza, kayak, or ketchup. Make a list of five and guess where each one came from.
5. Why Do Many Robots Look Nothing Like People?
Pick a job, like watering plants or sorting laundry. Draw a robot built for that job. Does it need legs, wheels, or arms? Does it need a face?
6. Why Do Engineers Sometimes Build Robots in Human Shapes?
Walk around your home and count things made for human size and shape, like door handles, stairs, and light switches. Which would be hard for a robot without hands or legs?
7. Why Does Every Robot Need a Body, a Brain, and a Power Source?
Pick a robot toy, or draw a robot. Label the body, the brain, and the power source. Which one would you notice first if it were missing?
8. How Does a Robot Get the Energy to Move?
Look at the outside of a toy or gadget with a grown-up. Does it use batteries, a plug, or solar cells? Make a list of three gadgets and how they get their energy. Don’t open any battery covers.
Do this with a grown-up9. What Does a Robot's Brain Actually Do?
Play robot brain with a friend. Your friend holds up a number card from 1 to 10, like a sensor reading. Your rule: if the number is 5 or more, say “stop”; if it is less, say “go.” Then switch roles and invent a new rule.
10. Why Do Robots Keep Repeating Sense, Think, Act?
Think about catching a ball. What do you sense? What do you decide? What do you do? Then repeat. Write the three steps in a circle, and add an arrow that goes back to the start.
11. Why Can a Robot Do the Same Job Thousands of Times Without Getting Tired?
Cut out 60 paper squares in three sizes, mix them up, and sort them into piles by size. Time each batch of 20. Do you get slower or make more mistakes near the end? A robot would not. What else would it need?
Do this with a grown-up12. Why Are Some Easy Things for People Really Hard for Robots?
Try picking up a coin from a table and dropping it in a jar while wearing thick winter mittens. What did you lose when your sense of touch got dulled? How does it feel?
13. Why Does a Robot's Weight Matter So Much to Designers?
Fill a backpack with books and carry it around the room. Then take out half. How does the weight change how easily you move, and how tired you feel? A robot has the same trouble.
14. Why Isn't a Laptop a Robot?
Draw a laptop and add the parts it would need to become a robot. Which parts would let it sense? Which would let it act? What would you add first?
15. Why Was the First Factory Robot Just an Arm?
Use your own arm to pick up five different things, like a pencil, a book, and a cup. Count what your arm does each time: reach, grip, lift, turn, and put down. A robot arm does the same.
16. Why Aren't Real Robots as Clever as Robots in Movies?
With a grown-up’s permission, pick a movie robot. Write three things a real robot can do today and three things it cannot do. Which things in the movie were pretend?
Do this with a grown-up17. Why Do Engineers Draw a Robot Before They Build It?
Sketch a robot that helps carry groceries. Label its wheels or legs, its sensors, its arms, and where the groceries go. Show your drawing to someone and ask what they would change.
18. Why Do Engineers Test a Robot Again and Again?
Make a paper airplane and throw it ten times. Mark where each one lands. Is it always the same? Change one thing, like the fold, and test again. Which change helped?
19. Why Do Robots Have Emergency Stop Buttons?
Look for red emergency stop buttons or pull cords in public places, like gyms or elevators, with a grown-up. Where are they? Why is it important that they are easy to see and reach?
Do this with a grown-up20. Why Are Some Big Robots Kept Behind Safety Fences?
Use masking tape to mark a “safety zone” around a toy on the floor. Practice staying outside the line while a friend moves the toy. Why does the line help in a busy room?
Do this with a grown-up21. Why Can Some Robots Work Safely Next to People?
Make a list of three safety features that a robot working next to people should have. Draw it with arrows to each feature. What would make you feel comfortable working next to it?
22. What Does It Mean When a Robot Is Autonomous?
Rank four gadgets from “a person controls everything” to “works by itself,” like a remote car, a robot vacuum, a toaster, and a drone. Explain why you put each one where you did.
Do this with a grown-up23. Why Do Some Robots Need a Person to Steer Them From Far Away?
Ask a friend to move a toy car across a table to a cup by following only your spoken commands, like “forward” and “left.” Next, wait three seconds after each command. How does the delay change the task?
24. Why Do Engineers Send Robots to Places That Are Too Hot, Too Deep, or Too Far for People?
Pick a place that is hard to visit, like the deep ocean or the surface of Mars. List three problems for people and three ways a robot would solve them.
25. How Small Can a Robot Get, and How Big?
Mark out 17 meters outside by walking about 20 big steps. That is the length of Canadarm2. Now look at a grain of rice. How many grains would it take to cover the same distance?
Do this with a grown-upExpedition 2: Sensors That Notice (25)
26. What Is a Sensor, and Why Do Robots Need Them?
Make a two-column list. In one column, list your senses: sight, hearing, touch, smell, and balance. In the other, write a robot sensor that does a similar job for each one.
27. How Does a Bump Sensor Tell a Robot It Has Hit a Wall?
Tape two strips of foil to cardboard so they just miss each other. Press them together and see them touch. Draw how a battery and a light could be wired in so the light turns on when they touch.
Do this with a grown-up28. How Does a Robot’s Ultrasonic Sensor Find How Far Away a Wall Is?
Now, be a detective! An echo returns to a robot after 0.01 seconds. Sound goes 343 meters each second. How far away is the wall? Remember, the sound goes there and back, so divide your answer by two!
29. How Does a Robot Use a Laser Beam to Map the Space Around It?
Now, take the explorer task! Stand in the middle of a room. Walk in a straight line to the wall in eight directions, and count your steps each time. Draw a map from your numbers. That is how lidar draws its map!
30. Why Can a Robot Follow a Black Line on the Floor?
Draw a thick, curvy black line on white paper. A friend moves a small card along it and calls out “dark” or “light.” Can you steer using only those two words?
31. How Does a Robot Know Which Way Is Up?
Tie a small weight, like a washer, to a string and hold the string. It always hangs straight down. Tilt your hand and see how the string stays pointing down. How could a robot use that?
32. How Does a Robot Know How Far It Has Driven?
Mark a spot on the edge of a can or a coin. Roll it along a ruler and count the turns. Multiply the turns by the distance around it. Does it match the distance you rolled?
Do this with a grown-up33. Why Do Some Robots Have Touch-Sensitive Skin?
Draw a robot hand and mark the places you would put touch sensors. Which parts of a person’s hand have the most touch sensors? Where on your own hand is it easiest to feel a light touch?
34. How Can a Robot Use a Camera to Find a Ball?
Draw a 10-by-10 grid on paper. Color some squares to make a ball. Then find the center square of the ball. This is how a robot finds the ball in the grid.
35. Why Do Robots Sometimes Get Confused by Bright Sunlight?
Look at a phone or tablet screen in a bright window and then in the shade. Which is easier to read? Never look directly at the Sun. How is the screen like a sensor in bright light?
36. Why Do Robots Use Many Sensors Instead of Just One?
Put an object in a bag. Try to guess it by touch only. Then guess by touch and by shaking it to hear it. Is it easier with two senses? Why do robots use many sensors?
37. How Does a Robot Sense Heat?
Fill a mug with warm tap water. Hold the back of your hand near the mug, without touching it, and slowly move it closer and farther. Can you feel the heat? A sensor does this with numbers.
38. Why Can a Robot Turn Toward a Clap?
Sit in a chair with your eyes closed while a friend claps in different spots around the room. Turn your head until the clap seems to come straight ahead. That is what the robot does.
39. Why Does a Robot with a Light Sensor Follow a Flashlight?
Act it out: a friend shines a flashlight on the floor ahead (never at eyes). You pretend to be the robot, and you turn left if they say “left is brighter,” and right if they say “right.” Can you reach the light?
40. Why Do Robots Use GPS Outdoors but Not Inside?
Now, take the challenge! With a grown-up, open a map app on a phone outside, then inside the middle of a building. Watch the blue dot. Is the dot steady outside? Does it stay in the right place? What happens inside?
Do this with a grown-up41. Why Doesn't a Robot Vacuum Fall Down the Stairs?
With a grown-up, slowly push a toy car across a flat table toward the edge. Pretend your eyes are the cliff sensor: stop the car as soon as the table disappears below its front wheels. Put a pillow on the floor to catch it. What change tells the sensor to stop?
Do this with a grown-up42. Why Do Robot Sensors Sometimes Get Things Wrong?
Ask three friends to guess the length of a table by eye, then measure it with a tape. Compare each guess with the average of the three. Was the average closer to the real length?
43. Why Do Automatic Doors Open as You Walk Up?
At a store with a grown-up, look above an automatic door for the sensor box. Walk up slowly, then quickly. Does the door open at the same distance? Where does the sensor look?
Do this with a grown-up44. How Does a Robot Arm Know When It Has Reached the End of Its Swing?
Slide a drawer open until it stops at the end. How did you know to stop? Did you see it, feel it, or hear it? Which of your senses is like a limit switch?
45. How Can a Magnet Tell a Robot Where Its Parts Are?
Use a fridge magnet and a paper clip. Slowly move the magnet toward the clip and notice how close it needs to be to move it. This is how a sensor feels a magnet’s pull.
46. How Does a Robot Hand Know How Hard to Squeeze?
Use tongs to lift a marshmallow, a grape, and a pebble. For each one, close slowly and stop right when you feel it grip. Can you do it with your eyes closed?
47. How Does a Light Curtain Stop a Factory Robot When Someone Gets Close?
In a dim room, aim a flashlight at a sheet of paper. Wave a hand through the beam. Watch the shadow on the paper appear. The sensor would notice that change too.
48. How Can a Robot Sort Red Blocks From Blue Ones?
Sort a handful of colored blocks or candies into groups. Write your rule for each group, like “if it’s mostly red, it goes here.” Then ask a friend to follow only your rules.
49. Why Do Some Robots Carry Gas Sensors?
With a grown-up, find the smoke alarms and the carbon monoxide alarm in your home and make a note of where each one is. Never press, test, or open an alarm without a grown-up. Why is it smart to have them in different places?
Do this with a grown-up50. How Does a Robot Find Its Charging Station?
Play “warmer, colder” in a clear room: one person hides a small object, and the other searches while the first says “warmer” or “colder.” How is that like a robot following a signal that gets stronger?
Expedition 3: Motors, Joints & Wheels (25)
51. Why Does a Motor Spin When You Connect a Battery?
Hold two fridge magnets near each other. Feel them push apart and pull together. A motor uses this same push and pull, with the timing controlled so the spinning never stops.
52. Why Do Robot Motors Have Tiny Gearboxes?
With a grown-up, look at the gears on a bicycle. Which gear is easiest for climbing hills? Which is best for going fast on flat ground? Why do the two differ? Talk about it!
Do this with a grown-up53. What Is a Servo Motor?
Play servo: a friend shows an angle on a card, like 0, 45, or 90 degrees. Point your arm to that angle and hold it. Can you stay still when your friend gently nudges your arm?
54. Why Can a Stepper Motor Move in Tiny, Exact Steps?
Cut out a paper circle and mark 20 equal steps around the edge. If each step turns it the same amount, how many degrees is one step? How many steps make a half turn?
Do this with a grown-up55. Why Do Robots Use Wheels More Often than Legs?
Push a toy car across a floor. Then drag or carry a block of the same weight the same distance. Which way takes less effort? Which would be better on a staircase?
56. Why Do Many Walking Robots Have Four Legs?
Stand on two feet, then on hands and knees. Try lifting one hand or knee. Which position feels steadiest? How does that help explain why four-legged robots are easier to build?
57. Why Is Balancing on Two Legs Such a Challenge for a Robot?
Stand on one foot with your arms out, next to a wall or chair and with a grown-up nearby. Wobble a bit and notice the small corrections you make. Now close your eyes for a moment. Is it harder? Which senses were helping you balance?
Do this with a grown-up58. How Does a Robot Turn by Spinning Its Wheels at Different Speeds?
With a partner, link arms side by side so each of you is a wheel. Walk forward together. To turn right, the left person takes bigger steps. How do you spin in place?
59. Why Do Some Robots Have Tank Treads?
Press a flat hand into a tray of flour or soft clay, then press only your fingertips. Which one sinks in more? How does it explain why treads help in soft ground?
60. Why Do Some Robots Roll on Balls or Special Sideways Wheels?
Try moving sideways like a crab, then forward, then diagonally, without turning your body. A regular wheel can’t do that. Draw a wheel with angled rollers around the edge.
61. Why Do Robot Arms Have Joints Like a Shoulder and an Elbow?
Hold your elbow still against your side and try to scratch the top of your head. Not easy! Now count how many joints you used when you could reach it. What does that tell you?
62. Why Does a Robot Arm Need About Six Joints to Reach Anywhere?
Hold a pencil in the air. Move it up, sideways, and forward. Those are three directions. Now twist it three ways: tilt, turn, and roll. That makes six. Can you do all six?
63. How Does a Robot Gripper Pick Up Things?
Pinch a smooth plastic bottle with two craft sticks and lift it. Then wrap a rubber band around the tips of the sticks and try again. Does the rubber help?
64. Why Do Some Robot Hands Use Suction Cups?
Press a rubber suction cup against a smooth tile, a bumpy towel, and a wet window. On which does it stick best? Why does a rough surface let the air slip in?
65. Why Are Some Robots Soft and Squishy?
Draw a finger with air chambers along one side. When air goes in, which way does it curl? Compare with squeezing a sponge. Why is soft handy for picking up a strawberry?
66. Why Does a Long Robot Arm Lift Less than a Short One?
Hold a full water bottle close to your body, then straight out at arm’s length. Which is harder to hold? Your shoulder is like the robot’s motor, working harder with a longer reach.
67. Why Do Robots Use Belts and Pulleys?
Loop a rubber band around two bottle caps or spools on a table. Turn one and watch the other. Try with a small one turning a larger one. Which spins faster?
68. Why Do Robot Motors Get Warm?
Rub your palms together fast for 20 seconds. Feel the heat? Rubbing turns motion into heat. Where else in a robot might moving parts rub and warm up?
69. How Does a Robot Arm Know Exactly Where Its Hand Is?
Close your eyes and touch your nose with your finger. How did you know where your hand was without looking? Robots use sensors in joints for the same job.
70. Why Does a Robot Sometimes Overshoot Its Stop and Wobble Back?
Place a mark on the floor. Slide a toy car and try to stop it right on the mark by giving it gentle pushes. Does a slower approach help you land closer?
71. How Can a Robot Jump or Hop?
Crouch low and jump as high as you comfortably can, landing softly with bent knees. Then try a tiny hop. Which goes higher? Your bendy legs store and release energy like a spring. Stop if anything hurts.
72. Why Do Some Robots Wriggle Like Snakes?
Make a snake from a chain of linked paper clips or a paper-strip chain. Move it by making an S-shaped wave along it. Which way does it move compared with the wave?
73. How Can a Robot Balance on Just Two Wheels?
Balance a long ruler or a broom handle upright on your palm. Move your hand to keep it from falling. Which way do you move your hand when it leans? That is what the wheels do.
74. Why Do Some Strong Robots Push with Air or Liquid?
With a grown-up, connect two plastic syringes (no needles) with a short tube full of water. Push one plunger and watch the other move. What do you notice about how the push travels?
Do this with a grown-up75. Why Do Robot Builders Choose Lightweight Materials?
Roll a sheet of paper into a tube and tape it. Stand a stack of books on it. Then try the same paper flat. Which holds more? What does the shape do?
Expedition 4: Helper Robots at Work (25)
76. How Does a Robot Vacuum Map a Room?
Draw a map of your bedroom as seen from above. Mark the bed, desk, and doors. Then draw the path a robot vacuum might take to cover every part of the floor without missing any.
77. Why Do Robot Vacuums Get Stuck on Socks and Cords?
Do a “robot-ready” tidy-up of your room: pick up socks, cords, and small toys from the floor. How much floor space did you clear? Which things would have trapped the brush?
78. Why Does a Robot Lawn Mower Stay Inside the Yard?
Lay a string around a patch of floor to make a boundary. A friend acts as the mower, walking forward slowly and turning around whenever their toe touches the string. Will they stay inside? Keep the floor clear of trip hazards.
79. How Do Pool-Cleaning Robots Clean Underwater?
Mix a spoonful of soil in a jar of water. Pour it through a coffee filter into another jar. What got caught? That is how a pool robot’s filter bag gets dirt out of the water.
80. How Do Window-Cleaning Robots Stick to Glass?
Draw a plan for a window-cleaning robot. Show where the sensors that find the frame edge go. How would the robot know it had cleaned the whole window?
81. Why Do Warehouses Use Flat Robots That Carry Shelves?
Set up a mini warehouse with shoebox shelves. One friend is the robot who carries a shelf to a “packer,” who picks out one item. How does moving the shelf instead of the person change the job?
82. How Do Factory Robots Paint Cars So Evenly?
Use a brush to paint a strip of paper while moving slowly, and another strip while moving fast and slowing down. Which strip is smoother? Why does steady speed matter?
83. How Can a Robot Pick a Strawberry Without Squishing It?
Paint or color five strawberries from green to white to pink to red. Which color would a robot pick? Write the rule: “Pick the berry when it is mostly this color.”
84. Why Do Farm Robots Drive Along the Crop Rows?
Plant bean seeds in a tray of soil in neat rows, using a ruler and string to keep the lines straight. Why does a straight row make it easier for a robot to travel between the plants?
85. How Do Robots Sort Recycling?
With a grown-up, sort some clean recycling into groups by material, following your local rules. Which items were tricky to tell apart? What sensor would help a robot decide?
Do this with a grown-up86. What Is Canadarm2, and What Does It Do?
Look at a picture of Canadarm2 on a Canadian five-dollar bill or online with a grown-up. Where would its elbow be? How is the arm like your own arm?
Do this with a grown-up87. How Do Small Robots Crawl Through Pipes to Find Leaks?
Look through a long cardboard tube with a flashlight at one end. What can you see and what is hard to see? Roll a toy car through the tube. How would you put a camera on it?
88. Why Do Robots Climb Wind Turbines and Tall Towers?
Draw a robot that climbs a tall pole. How would it hold on? What would it carry to check for damage? Make a list of its parts and explain what each one does.
89. Why Do Delivery Robots Roll Along Sidewalks?
Write three rules for a sidewalk robot, like how fast it should go, who goes first at a crossing, and what to do when someone is in the way. Why is slow better?
90. How Can Small Robots Help Search a Collapsed Building?
Pile cushions and boxes to make a tunnel with gaps. See which toy fits through. Design a tiny robot that could go through the smallest gap. How would it see in the dark?
91. How Do Robots Scrub the Bottoms of Big Ships?
Drag a smooth plastic lid through a tub of water. Then stick bits of clay to the bottom of the lid and drag it again. Which feels harder to move? Why does a clean hull help a ship?
92. How Can a Robot Build a Brick Wall?
Play brick robot with a friend. One of you reads a drawing of a small wall, and the other places toy blocks exactly where the plan says. Does the wall match the drawing?
Do this with a grown-up93. Why Do Robots in Science Labs Move Tiny Drops of Liquid?
Use a dropper to put exactly ten drops of water into each of five cups. Do the cups hold the same amount? Pour each into a measuring cup to check. Why does a machine help with this?
94. Why Do Greenhouse Robots Check Plants One by One?
Plant a bean seed and measure its height with a ruler every day for two weeks. Draw a chart of the numbers. What would you have the robot check each day?
95. Why Can Some Robots Work in Total Darkness?
In a dim room with a grown-up, find three objects using only touch and sound. List the senses you used. Which robot sensors work in the same way?
Do this with a grown-up96. How Do Warehouse Robots Avoid Bumping Into Each Other?
Make a crossroads with masking tape on the floor. Two friends are robots, each carrying a toy. Make rules for who goes first and who waits. Do they bump? What rule fixes it?
97. How Do Robots Pack Cookies Without Breaking Them?
Try moving dry cereal pieces from one bowl to another with a plastic spoon, then with your fingertips pinched hard. Which way breaks fewer? How would a robot gripper be gentle?
98. Why Do Robots Clean Solar Panels?
Rub a little chalk dust or flour on a clear plastic folder. Hold it up to a window and see how much light comes through. Wipe half clean. Where is it brighter?
99. How Do Robots Sort Parcels So Fast?
Write ten names of cities on cards. Sort them into bins by the first letter as fast as you can, and time it. How could a scanner and a computer do it?
100. Why Can't One Robot Cook, Clean, and Fold Laundry Yet?
Write down every step to fold a T-shirt as clearly as you can. Have a friend follow only your words. Which steps were hard to explain? Which would need sensors?
Expedition 5: Drones, Rovers & Explorers (25)
101. Why Do Most Small Drones Have Four Rotors?
Look at pictures of drones and count the rotors. Draw a drone with four rotors in a square. Why do you think the rotors are spread out to the corners instead of in a line?
102. How Does a Drone Stay Level in the Air?
Balance a ball on a flat plate or tray. Keep it in the middle by tilting the plate whenever it rolls. Your hands and eyes do the job of a drone’s sensor and motors. How fast must you be?
103. Why Do Two of a Drone's Propellers Spin One Way and Two the Other?
With blunt scissors and a grown-up nearby, cut two paper spinners and bend the blades in opposite directions on each. Drop them from the same height. They twirl opposite ways. How would you pair them to cancel the twist?
Do this with a grown-up104. Why Does a Drone Tilt to Fly Forward?
Put a small paper boat or a feather on a table. Blow through a straw straight down on it, and then blow from a slant. When does it slide? How is that like a tilted drone?
105. Why Can't Most Drones Fly for Very Long?
Hold a light paperback book out at arm’s length and time how long you can last. Stop when your arm feels tired. Your arm tires out like a battery. What would make your arm last longer?
Do this with a grown-up106. Why Do Some Drones Have Little Cages Around the Propellers?
With a grown-up and blunt scissors, use craft sticks and straws to build a guard around a paper propeller on a pencil. Can you still spin it? Gently bump it into a wall. Does the guard help? Keep small parts away from little kids and pets.
Do this with a grown-up107. Why Must Drones Stay Away From Airports and Crowds?
Draw a map of your neighborhood. Color places where a toy drone should never fly, like crowds, playgrounds, and roads, in red. Where would be a safe spot, with a grown-up in charge?
Do this with a grown-up108. How Can a Drone Help a Farmer Check a Big Field?
Look at your lawn or a park from an upstairs window or hill. Can you spot greener and browner patches? Draw a map, color the patches, and mark where you would check first.
109. How Do Drones Make Maps and 3D Models?
Hold a finger up at arm’s length. Close one eye, then the other, and watch your finger jump against the background. That jump tells your brain how far away it is. Photos can do this too.
110. Why Can Drone Light Shows Paint Pictures in the Night Sky?
Draw a 10-by-10 grid on paper. Color dots to draw a heart. Then make a second grid for a star. If a drone moved from one dot to the next, which would go farthest?
111. How Do Delivery Drones Carry Packages?
Make a winch from a pencil, a string, and a small paper cup. Turn the pencil to wind the string and lift the cup, then unwind to lower it. What would you do to stop the cup from spinning?
112. How Do Scientists Use Drones to Study Tall Trees and Forest Canopies?
Look up at a tall tree with a grown-up. List three things in the top that you cannot see well from the ground. How could a drone help you see them?
Do this with a grown-up113. Why Can a Drone Hover but an Airplane Can't?
Hold a paper strip just below your lower lip, and blow across the top. The strip lifts up! Now make a paper airplane and watch it glide forward. What does the plane need that a drone does not?
114. Why Is a Rover Not Just a Small Car?
Imagine your family car could never be fixed or refueled for years. List what it would need. Which three parts would you make extra strong? Compare your list with a rover's design.
115. How Does a Rover Keep Its Wheels on the Ground Over Bumpy Rocks?
Draw a seesaw with a wheel on each end and a body in the middle. Show what happens when the left wheel goes up over a rock. Does the middle go up as far as the wheel?
116. Why Does a Rover Only Drive a Little Bit at a Time?
Write ten steps to guide a friend, who has closed eyes, across a cleared room. Give the whole list at once, and they cannot ask questions. What goes wrong? Where would you add safety checks?
117. Why Do Rovers Carry Rock-Zapping Lasers and Drills?
With a grown-up, look at a lamp or bright window through an old CD, being careful never to look at the Sun. You will see colors spread out. Different lights spread out in different patterns.
Do this with a grown-up118. How Do Rovers Get Power on Other Worlds?
Put a small solar garden light or toy in a sunny window and in a shady corner. Compare how it works. What would you do if the Sun was hidden by dust for days?
119. Why Do Rovers Have Cameras on Tall Masts?
Crouch low and look across a field or street, then stand and look again. Find a safe step or low wall, with a grown-up, to stand on. How does height change what you can see?
Do this with a grown-up120. Why Do We Send Rovers to the Moon?
Mix flour and a little cocoa to make pretend Moon dust in a tray. Roll toy wheels through it. Which wheels sink or slip? How would you design wheels for a dusty surface?
121. How Do Underwater Robots Take Pictures in the Dark Deep?
In a dim room with a grown-up nearby, find a toy by touch alone. Then find it with a flashlight (never shine it at eyes). What does a deep-sea robot need that you needed? Draw a robot with lights.
Do this with a grown-up122. Why Do Some Underwater Robots Glide by Changing Their Weight?
With a grown-up, fill a plastic bottle with water. Drop in a small dropper with a little air in it, and put the cap on. Squeeze the bottle, and the dropper sinks! Release, and it rises.
Do this with a grown-up123. How Do Robots Explore Caves That Are Too Narrow for People?
Measure the width of a few holes in a cardboard wall using a ruler. Which of your toys would fit through each one? What shape of robot would fit through the tightest gap?
124. Why Do Engineers Copy Animals When They Build Robots?
Pick an animal and draw a robot that copies one of its skills, like climbing, swimming, or squeezing through gaps. Label the part you copied and explain why it works for your robot.
125. Why Do Swarms of Tiny Robots Work Together Like Ants?
Play swarm: each friend tries to stay about two steps from the nearest person while moving slowly around a room. No one is the leader. What shapes appear? What if one person stops?
Expedition 6: Robot Brains & Build-It Ideas (25)
126. How Does a Robot Decide What to Do Next?
Draw a flowchart for a robot crossing a room. Use boxes for “Is something in the way?” and “Drive forward.” Add arrows for yes and no. Test it by following your own chart.
127. Why Must Instructions for a Robot Be So Exact?
Write steps for drawing a smiley face, using only simple moves like draw a circle and put two dots inside. A friend follows only what you wrote. What did they draw? What was missing?
128. Why Do Robot Instructions Use If-Then Rules?
Write five if-then rules for a robot crossing the street with a grown-up, like “If the signal shows a red hand, then wait.” Try acting out each one with a friend.
Do this with a grown-up129. Why Does a Robot Check, Act, and Check Again?
Toss a soft ball toward a bucket. First toss once without changing your aim. Then toss five times, changing your aim after each try. Which gets closer? Why does checking after each move help a robot?
130. Why Can a Robot Get Out of a Maze by Always Turning Left?
Draw a maze on paper. Put your finger at the entrance and always keep your left hand on the left wall. Do you reach the exit? Draw a different maze where this rule would fail.
131. Why Do Robots Need Maps or Landmarks?
Draw a map of your path from your bed to the kitchen, using landmarks like doors and furniture. Add the number of steps between them. A friend follows your map with their eyes open.
132. Why Do Robots Take Tiny Measurements Many Times a Second?
Lay a long strip of masking tape on the floor. Push a toy car along it while a friend tells you to look at the tape only once every five seconds. Then look every second. Which keeps the car straighter?
133. Why Can a Robot Fail Even When It Follows Every Step Perfectly?
Write steps for a friend to drive a toy car to a cup, like “go forward three feet.” While they are out of the room, quietly move the cup. Follow the steps exactly. Where does the car end up? What step could you add so it notices?
134. How Does a Robot Know When Its Job Is Finished?
Write a “done” test for cleaning up toys. What would a sensor see when all the toys were put away? Is it easy or hard to test? How would a robot do it?
135. What Does a Robot Do When Something Blocks Its Path?
Set up a route with a box blocking the middle. A friend must follow the rule, “Walk forward. If blocked, turn right, take two steps, then turn left.” Does it get around the box?
136. Why Do Some Robots Remember Where They Have Been?
Walk through a room, leaving a trail of sticky notes on the floor. Then walk back following only the notes, picking them up in order. Why would a robot like a trail to follow?
137. How Can a Robot Arm Learn by Trying Again and Again?
Toss a ball into a bucket ten times from the same spot. After each throw, change one thing, like how hard or how high. Write down hits and misses. Did you get better with practice?
138. Why Do Builders Test Robot Ideas with Cardboard First?
Build a cardboard model of a robot that carries a note across a table. Test it with tape, and change one thing. What did the model show you that the drawing could not?
139. What Happens at a Kids' Robot-Building Contest?
Set up a mini contest at home: build a device from cardboard and tape that moves a ping-pong ball across a table. Decide the rules and scoring. Who made the best attempt? Why?
140. How Can a Game of Robot Says with a Friend Show How a Robot Reads Steps?
Play Robot Says with a friend using 5 commands: forward, back, turn left, turn right, and stop. Can you guide the robot to a chair? What steps did you leave out at first? Swap roles and play again!
141. How Can You Build a Cardboard Robot Arm That Really Grips?
With a grown-up, cut four cardboard strips. Join two with a paper fastener for the arm. Join two more as pincers on the end. Tie a string to pull them closed. Try picking up a pom-pom.
Do this with a grown-up142. Why Do Robot Builders Wear Safety Glasses?
Make a workshop rules poster with a grown-up: glasses on, hair tied back, tools put away, and ask a grown-up for anything sharp or hot. Hang it where you build.
Do this with a grown-up143. Why Do Robot Batteries Need Extra Care?
With a grown-up, find the battery drop-off place near you and make a list of battery rules: right charger, no damage, charge where a grown-up can see, and recycle. Button and coin batteries are dangerous if swallowed, so tell a grown-up at once.
Do this with a grown-up144. How Do the Parts of a Robot Send Messages to Each Other?
Make a line of friends. Each holds hands. The first squeezes the second’s hand, which passes the squeeze along. Pretend the first is a sensor, the last a motor. How long does the message take?
145. Why Are the Best Robots Often the Simplest?
Draw a robot with ten parts. Cross out three that it could manage without. Will it still do the job? Which part is the hardest to give up?
146. Why Do Some Robots Wait for a Signal Before They Start?
Play Red Light, Green Light as a robot that only moves on the “green” signal. What is the signal? What happens if you start before the signal? How does this help prevent crashes?
147. Why Do Engineers Try to Build Robots From Parts That Can Be Reused or Recycled?
With a grown-up, find an electronics recycling drop-off or a repair event near you. List which parts of a toy robot, like wheels or motors, could be reused if the toy broke.
Do this with a grown-up148. How Do You Keep a Robot Working for Years?
Write a care checklist for a robot vacuum: empty the bin, clean the brush, wipe the sensors, and check the wheels. Ask a grown-up to help you try each step on a real vacuum.
Do this with a grown-up149. Why Do Inventors Start with a Problem Before They Design a Robot?
Write a one-sentence problem you would like to solve, like “my plants get dry when I’m away.” List three ways to fix it. Is a robot the simplest answer?
150. What Could Robots Help Scientists Explore Next?
Plan a robot mission. Pick a place to explore, then list three questions scientists want to answer and three parts your robot needs. Draw it and give it a name.