Decimal addition & subtraction lesson
Decimal numbers addition & subtraction
Decimal addition/subtraction is done similar to the whole number addition/subtraction.
Write the decimal numbers vertically and make sure that the decimal points are aligned (second one is directly below the first one).
If number of digits after the decimal point (fractional part) is not equal in both the number then add trailing zeros to make it the same size.
Add/subtract the numbers and write the decimal point of the result below the other decimal points.
Example: Add the following numbers: 42.704 and 35.9
1. First number is 42.704 and Second number is 35.9; Write the numbers in proper columns.
2. Add two zeros to the second number (35.9). Modified second number is 35.900
3. Add the numbers and place the decimal point after the third digit from the right of the result (or below the other decimal points)
Example: Subtract the following numbers: 482.7 and 135.91
1. First number is 482.70 and Second number is 135.91; Write the numbers in proper columns.
2. Add one zero to the first number (482.7). Modified second number is 482.70
3. Add the numbers and place the decimal point after the second digit from the right of the result (or below the other decimal points)