pxt-calliope/docs/courses/csintro/conditionals/activity.md

Activity: Rock, paper, scissors

For this activity, each student will need a micro:bit. Everyone will create the same program, the classic rock paper scissor game.

Introduce activity

• Have students recall the classic rock paper scissors game.
• What are the rules of the game? What are the conditionals?

Example: If Player A gets rock, and Player B gets scissors, Then Player A wins.

• Have students write the pseudocode for how to play the game on the micro:bit.

Example pseudocode:
On button A press: choose random number from 0-2 If random number = 0, then display rock icon, Else if random number = 1, then display paper icon, Else display scissors icon.

• Point out that because there are only three possibilities, we don’t need to do a separate check to see if random number = 2. So we just use an else.

micro:bit

• Working from the specifications, have students work in pairs to try to code a Rock Paper Scissors game on their own.
• If students get stuck, there is a tutorial at https://pxt.microbit.org/projects/rock-paper-scissors (steps 1 through 4), that leads students step-by-step through the process of coding a working rock paper scissor game for their micro:bit.
• Let them play the game against their program.

Ideas for Mods

• Add a way to keep score: Steps 5 through 7 in the tutorial
• Mod the game to use different images or to add more options like ‘Rock Paper Scissors Lizard Spock’, Step 8 in the tutorial

See the activity online: Rock, paper, scissors