When you are adding or subtracting decimals you will often come across problems with decimals that may be missing a digit in various place values. Well, in this lesson, we will learn how we can insert zeros in the empty spaces to make the addition or subtraction easier for us!
Inserting Zeros for Addition
Let's say that we have a problem such as 24.5+3.2.
Remember that when you are adding or subtracting decimals, the decimal point needs to line up one on top of the other:
Now, as you can see, there is no digit in the tens place for the decimal number 3.2.
This is when you can insert a zero in the place where there are no digits.
Why add a zero?
Because zero holds no value so it won't change our problem!
That means that the sum of 24.5+3.2 equals 27.7!
Inserting Zeros for Subtraction
Let's say that we have the problem 18.79-12.3.
Now as you can see, there is no digit for the hundredths place in the decimal number 12.3.
This is when we insert a zero in the place where there are no digits.