Double or halve?

Adapted from NRICH

Collect resources

You will need:

  • 2 different coloured markers or coloured pencils​

  • something to write on​

  • a 6-sided dice or a 1-6 spinner

  • a 9-sided dice or a 0-9 spinner.

Watch the video to learn how to play

Transcript

OK, everybody, welcome back! We're here today to have a look at the game multiplication toss, which some people also call how close to 100. To play today I'm using a spinner, and I just made it by printing out a decagon and drawing lines across the opposite angles and labeling it from 0 to 9.

And I'm going to use my paper clip that I found in the drawer, and a pen and I can flick it...

Transcript coming soon.

How to play

  • Choose a target number between 0 - 100 and write this on your sheet of paper.

  • The first player rolls the dice and chooses whether to double or halve the number.

    • Record the roll.

  • Take it in turns to roll the dice, keeping a running total.

    • If a player can't go, they miss a turn.

  • The winner is the player who reaches the target number exactly.

Watch the video for another way to play

Discuss/reflect

  • Does it matter if you go first or second? Does it increase your chances of winning? Why or why not?

  • If you could play the same game again are there any moves you would change? Why or why not?

  • What are you thinking about in order to try to win the game?