Question

16. Jeremiah found the product of 31 and 29 as 899 by finding 30' and subtracting 1. Exptate how Jeremiah

could justify this approach.

Answer 1

31 x 29 = (30 + 1)(30 - 1) = 30² - 1

Explanation:

We can write 31 as (30 + 1)

We can write 29 as (30 - 1)

Therefore,

31 x 29 = (30 + 1)(30 - 1) = 30² - 1