Module 1 Practice Activities - Think Like a Coder

1 Morning Routine Algorithm Easy Screen-Free

Write an algorithm (a step-by-step list) for your morning routine, from waking up to leaving for school. Include at least 10 steps. Remember: be specific! Do not skip steps that seem obvious.

Hint: Think about all the small things you do that you usually do not even notice. Do you turn off an alarm? Do you stretch? Do you open your eyes first? The more detail, the better your algorithm!

Example algorithm:

Alarm goes off.
Open your eyes.
Reach over and turn off the alarm.
Sit up in bed.
Put your feet on the floor.
Stand up.
Walk to the bathroom.
Pick up your toothbrush.
Put toothpaste on the toothbrush.
Brush your teeth for two minutes.
Rinse your mouth with water.
Walk to your bedroom.
Open your dresser drawer.
Pick out clothes for the day.
Get dressed.
Walk to the kitchen.
Sit down at the table.
Eat breakfast.

Your algorithm will be different -- that is perfectly fine! The important thing is that every step is clear and in the right order.

2 Spot the Bug Easy Screen-Free

These instructions for making a paper airplane have bugs (mistakes). Can you find all the problems and fix them?

Fold the paper in half the long way.
Throw the airplane.
Fold the top corners down to the center fold.
Unfold the paper.
Fold the pointed top down about two inches.
Get a piece of paper.

Hint: The steps are in the wrong order! Think about what needs to happen first, second, third, and so on.

Correct order:

Get a piece of paper. (was step 6)
Fold the paper in half the long way. (was step 1)
Unfold the paper. (was step 4)
Fold the top corners down to the center fold. (was step 3)
Fold the pointed top down about two inches. (was step 5)
Throw the airplane. (was step 2)

The bugs: The steps were completely out of order! You cannot throw an airplane before you fold it, and you cannot fold paper you have not picked up yet. You also need to unfold after the first fold so you have a center line to fold the corners to.

3 Drawing Robot Medium Screen-Free

Work with your parent or a friend. One person writes instructions for drawing a simple picture (like a house, a tree, or a smiley face). The other person follows the instructions exactly and draws what is described. Compare the drawing to what the instruction-writer imagined. Do they match?

Rules:

The drawer cannot ask questions -- they can only follow the written instructions.
The instruction-writer cannot watch while the other person draws.
Use instructions like: "Draw a line from the bottom left corner to the bottom right corner" or "Draw a circle in the center of the page about the size of a quarter."

Hint: Be as specific as you can about where things go, how big they are, and what shape they are. Words like "big," "small," "over there," and "sort of round" are too vague. Try using measurements or comparisons instead.

4 Scratch: Sprite Conversation Medium Scratch

Open Scratch and make the cat have a conversation! Build a sequence of blocks that makes the cat:

Say "Hi! My name is Scratch Cat." for 2 seconds
Say "I like to dance!" for 2 seconds
Move 50 steps to the right
Say "Watch me move!" for 2 seconds
Move 50 more steps
Say "Ta-da!" for 2 seconds

Start your sequence with the "when green flag clicked" block from Events.

Hint: You need blocks from three categories: Events (the green flag block), Looks (the "say" blocks), and Motion (the "move" blocks). Snap them together from top to bottom in the order listed above.

Solution: Stack these blocks from top to bottom:

Events: "when green flag clicked"
Looks: "say [Hi! My name is Scratch Cat.] for [2] seconds"
Looks: "say [I like to dance!] for [2] seconds"
Motion: "move [50] steps"
Looks: "say [Watch me move!] for [2] seconds"
Motion: "move [50] steps"
Looks: "say [Ta-da!] for [2] seconds"

Click the green flag to run your program. The cat will say each message and move between them!

Tip: If the cat walks off the edge of the stage, drag it back to the left side before clicking the green flag again.

5 Scratch: Spin and Grow Medium Scratch

Make the cat do something new! Use these blocks to create a fun sequence:

Motion: "turn right 15 degrees" -- makes the sprite turn a little bit
Looks: "change size by 10" -- makes the sprite get bigger
Looks: "change size by -10" -- makes the sprite get smaller

Create a sequence where the cat turns, grows bigger, says something, turns more, and then shrinks back to normal size.

Hint: Start with "when green flag clicked." Then try: turn right 15 degrees, change size by 20, say "I am getting bigger!" for 2 seconds, turn right 15 degrees again, change size by -20, say "Back to normal!" for 2 seconds.

Solution: Stack these blocks:

Events: "when green flag clicked"
Motion: "turn right [15] degrees"
Looks: "change size by [20]"
Looks: "say [I am getting bigger!] for [2] seconds"
Motion: "turn right [15] degrees"
Looks: "change size by [20]"
Looks: "say [Even bigger!] for [2] seconds"
Looks: "change size by [-40]"
Looks: "say [Back to normal!] for [2] seconds"

Notice that the last "change size" block uses -40 to shrink the cat back. That is because we grew it by 20 twice (20 + 20 = 40), so we shrink by -40 to get back to the original size.

6 Invent Your Own Robot Game Challenge Challenge Screen-Free

Create your own Robot Game challenge for a family member or friend! You need to:

Set up a room with at least 3 objects placed in different spots.
Write down the goal (for example: "The robot must pick up the red ball, carry it to the table, and put it down").
Write out the complete list of instructions needed to complete the goal. Use only simple commands like STEP FORWARD, TURN LEFT, TURN RIGHT, PICK UP, PUT DOWN.
Count the total number of instructions.
Now try to figure out a SHORTER way to do it. Can you find a path that uses fewer instructions?

Hint: To find a shorter path, think about the most direct route. Could the robot face a different direction at the start? Could you move objects closer together? Finding the shortest solution is called optimization, and it is something real programmers work on every day!