Introduction

When multiplying decimals, first multiply the numbers together, then add up the number of decimal places shifted from to the left.

For example, $1.2*10$ , if we multiply $12*10$ , we get 120. The decimal shift in total is 1. So the answer is 12

Another example, $1.2*1.2$ , if we multiply $12*12$ , we get 144. The decimal shift in total is $1+1=2$ . So the answer is 1.44

When dividing decimals, multiply the top and bottom by sets of 10 until there are no decimal places left.

For example, $3.6/1.2=36/12$ , multiply both top and bottom by 10. The answer is therefore $36/12=3$ .