Multiplying and Dividing in 10s
# Multiplying and Dividing in 10s

Basic

Multiplying by 10, 100, 1000, moves the digits in each column (units, 10s, 100s, etc) to the left:

• multiplying by 10 moves all the digits 1 column to the left;

• multiplying by 100 moves the digits 2 columns to the left;

• multiplying by 1000 moves the digits 3 columns to the left.

Dividing by 10, 100, 1000 moves the digits in each column to the right:

• dividing by 10 moves them 1 digit to the right;

• dividing by 100 is 2 digits right;

• dividing by 1000 is 3 digits right.

The same is true for decimal numbers. Although the digits move, the decimal point stays in the same place.

## Examples

1. What is 34 x 100?

Answer: 3400

Move the 34 two digits to the left, filling the empty spaces with zeroes.

2. Given 34 x 23 = 782, what is 34 x 230?

Answer: 7820

230 = 23 x 10, re-write the question as 34 x 23 x 10. That makes the answer 10 times larger than the original question.

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