How to Subtract Decimals
Subtracting decimals is almost as easy as subtracting whole numbers. As long as you set up the problem correctly, you’re in good shape. Here’s how you subtract decimals:

Line up the decimal points.

Subtract as usual from right to left, column by column.

When you’re done, place the decimal point in the answer in line with the other decimal points in the problem.
For example, suppose you want to figure out 144.87 – 0.321. First, line up the decimal points:
In this case, you can add a zero at the end of the first decimal. This placeholder reminds you that in the righthand column, you need to borrow to get the answer to 0 – 1:
The rest of the problem is very straightforward. Just finish the subtraction and drop the decimal point straight down:
The decimal point in the answer goes directly below where it appears in the problem.