Today we continued to review different multiplication strategies in Math. We started with the break apart strategy that we have been using in previous classes:
Today we added a doubling and halving strategy to our list. Check out the example below:
In this example, you can double 5 to 10. This is a good choice because multiplying by 10 is something that we are able to do very quickly. However, it is important to remember that if you double one of the factors, you have to either half the other factor or half the answer. In this case, we decided to half the other factor. 12 split in half is 6. So, instead of multiplying 12 x 5 we multiply the easier 6 x 10. Since 6 x 10 = 60, we know that 12 x 5 = 60.