After a homework check and bell work, we reviewed multiplying and dividing by 10, 100, 1000, 10 000 etc. and decided on some rules to help us perform these operations. We came up with the rules below (please note – later on in the year we will cover this again and explain it in terms of moving the decimal place).

### Rule for multiplying by 10, 100, 1000, etc.

When you are multiplying you add as many zeroes to the product as there are in the factor if the factor is a multiple of 10 (10, 100, 1000, 10 000, etc)

Ex. 800 x 1 __000 000__ = 800 __000 000__

15 x 1__00__ = 15__00__

### Rule for dividing by 10, 100, 1000, etc.

When you are dividing a number that is a multiple of 10, 100, 1000, etc. (ex. has several zeroes at the end - 3400, 57 000,

99 000 000, etc.) by a multiple of 10 (10, 100, 1000, etc.), remove the number of zeros that are in your divisor.

Ex. 2 000 0__00__ ÷ 1__00__ = 20 000

700 000 __000__ ÷ 1__000__ = 700 000