When adding numbers with decimals the most important thing is to line up the decimal points of the numbers you are adding. If you do this, adding decimals is just like normal adding.
Here are some simple steps you can follow:
Write down the numbers vertically just like you would normally for addition. When doing this, be sure to line up the decimal points one on top of the other.
To make things easier, you can add in zeros as place holders to make the right sides of the decimal points the same length.
Add up the numbers, just like normal.
When you write down the answer, line up the decimal point with the numbers you added together. This is an important step. The decimal points of all the numbers, including the answer, should line up.
Examples:
1) 12 + 7.05 + .12 = ?
12.00
7.05 + 0.12
19.17
See how the decimal points all line up and how we added in zero's after the 12 and before .12 to make them line up easier.
2) 2.82 + 9.007 + 6 = ?
2.820
9.007 + 6.000
17.827
Subtracting Decimals
Subtracting decimals works exactly like adding decimals. Well, except for the subtracting part. Just like when adding decimals, the most important thing is to keep your decimal points lined up. Remember you can add in zeros to the right and to the left of the decimal point if it helps you to line things up.
