CS: Following Instructions Step by Step
Practice making and checking simple algorithms
CS: Following Instructions Step by Step
Practice making and checking simple algorithms
CS - Grade 2-3
- 1
Mia wants to brush her teeth. Put these steps in the correct order: A. Put toothpaste on the toothbrush. B. Rinse your mouth. C. Pick up the toothbrush. D. Brush your teeth.
Think about what must happen before toothpaste can go on the toothbrush.
The correct order is C, A, D, B. Mia should pick up the toothbrush, put toothpaste on it, brush her teeth, and then rinse her mouth. - 2
Follow these directions: Start at the star. Move right 2 spaces. Move down 1 space. Move left 1 space. Where do you end?
You end at the space that is 1 space to the right and 1 space down from the star. - 3
Sam wrote an algorithm to make a peanut butter sandwich: 1. Put the bread on a plate. 2. Eat the sandwich. 3. Spread peanut butter on the bread. What step is in the wrong place?
You cannot eat the sandwich before it is made.
Step 2 is in the wrong place. Sam should spread peanut butter on the bread before eating the sandwich. - 4
Write 4 steps to get ready for school in the morning. Number your steps 1 through 4.
Answers will vary. A good answer lists 4 steps in an order that makes sense, such as wake up, get dressed, eat breakfast, and pack your backpack. - 5
A robot can only understand these commands: forward, turn left, turn right, pick up. Write the 3 commands the robot needs to reach a ball that is straight ahead 2 spaces and then pick it up.
The ball is straight ahead, so the robot does not need to turn.
The correct commands are forward, forward, pick up. The robot moves ahead 2 spaces and then picks up the ball. - 6
Which instruction is clearer for a computer? A. Move a little bit. B. Move forward 3 steps. Explain your choice.
Instruction B is clearer because it tells the computer exactly what direction to move and how many steps to take. - 7
The steps for drawing a square are mixed up. Put them in order: A. Draw the left side. B. Draw the top side. C. Draw the right side. D. Draw the bottom side.
Start with any side, then keep going around the shape.
One correct order is B, C, D, A. This draws the top, right, bottom, and left sides to make a square. - 8
A computer follows steps exactly. What would happen if the steps say: 1. Put on socks. 2. Put on shoes. 3. Put on socks again.
Look for a step that repeats something already done.
The computer would try to put on socks two times. The last step is not needed because the socks are already on. - 9
Follow this algorithm and write the final number: Start with 5. Add 2. Add 1. Subtract 3.
The final number is 5. Starting with 5, adding 2 gives 7, adding 1 gives 8, and subtracting 3 gives 5. - 10
A bee starts on the flower. Directions: forward 1, turn right, forward 2. Draw or describe where the bee ends.
Do each command in order and remember that turning changes the direction the bee faces.
The bee ends 1 space forward from the flower and then 2 spaces to the right after turning right. - 11
Lena is giving steps to make a paper hat. She writes: 1. Fold the paper in half. 2. Decorate the hat. 3. Put the hat on. Which step might need more detail?
Step 2 might need more detail. Lena should explain how to decorate the hat, such as draw stars or add stickers. - 12
Choose the best algorithm to water a plant. A. Pour water on the floor, pick up the watering can, walk to the plant. B. Pick up the watering can, fill it with water, walk to the plant, pour water on the soil.
The best steps should help the plant get water.
Algorithm B is best because the steps are in a useful order and the water goes on the soil where the plant needs it. - 13
A robot starts in the middle square facing up. It follows these commands: forward, forward, turn left, forward. Mark where the robot ends.
The robot ends 2 squares above the start and 1 square to the left. - 14
Debug means to find and fix a mistake. Find the bug in this set of steps for washing hands: 1. Turn on water. 2. Dry hands with towel. 3. Use soap and scrub. 4. Rinse hands.
Hands should be dry at the very end.
The bug is that drying hands happens too early. The drying step should come after rinsing hands. - 15
Write an algorithm with 5 steps to guide a friend from the classroom door to their desk. Use clear direction words like forward, left, right, and stop.
Answers will vary. A good answer has 5 clear steps in a sensible order, such as walk forward 4 steps, turn right, walk forward 2 steps, turn left, and stop at the desk.