Doubling and halving

A number talk

Watch the video to see what to do

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.

Collect resources

You will need:

Items to create a mathematical model

  • pens or pencils

  • scissors

  • plain paper, grid paper or dot paper.

Discussion

  • Create a mathematical model to show how you could use doubling and halving to solve 6 x 8. You could use grid paper, dot paper, or even draw a comic strip!

  • Find 3 examples where doubling and halving isn't an efficient strategy. Why is it more efficient for some problems and not for others?