Decimals - Adding and Subtracting

 To add and subtract decimal numbers we can use the standard methods as shown in Written methods of Addition and Written methods of Subtraction. We just have to make sure that the decimal point is included and to be very careful to line up the numbers in their correct place value columns. The decimal points must line up.

Lets try an addition with decimal numbers: say,  4.23 + 3.14

As usual, we begin with the numbers in the column on the far right, in this case the 1/100 column.

5 - 3 = 2, put the 2 at the bottom of the column.

Next, we move on to the 1/10 column,

6 - 2 = 4, put the 4 at the bottom of the column.

Next, we move on to the units column,

5 - 2 = 3, put the 3 at the bottom of the column.

Next, we move on to the tens column,

2 -1 = 1, put the 1 at the bottom of the column.

The calculation is now complete,

25.65 - 12.23 = 13.42