Solve: 100 - 99.318 Decimal Subtraction Exercise

Question

Circle the correct answer to the following exercise:

100-99.318

Video Solution

Step-by-Step Solution

To avoid confusion in solving the exercise, we will add zeros in the appropriate places.

Three zeros for the number 100 and one zero before the number 99 as follows:

100.000099.318 100.000\\-099.318\\

Now let's solve the exercise in order:

Let's subtract the thousands after the decimal point:

08= 0-8=

Since we cannot subtract, we'll borrow ten from the ones digit of the whole number before the decimal point, since the other numbers are also zeros.

The ones digit of the whole number before the decimal point will become 0, and the tens digit of the whole number before the decimal point will become 10

We'll borrow ten from the tens digit of the whole number before the decimal point and it will change from 10 to 9, and now the hundreds digit of the whole number before the decimal point will become 10

We'll borrow ten from the hundreds digit of the whole number before the decimal point and it will change from 10 to 9, and now the tenths digit after the decimal point will become 10

We'll borrow ten from the tenths digit after the decimal point and it will change from 10 to 9, and now the hundredths digit after the decimal point will become 10

We'll borrow ten from the hundredths digit after the decimal point and it will change from 10 to 9, and now the thousandths digit after the decimal point will become 10

Now that we know how to solve the exercise, let's subtract the thousands after the decimal point:

108=2 10-8=2

Let's subtract the hundreds after the decimal point:

91=8 9-1=8

Let's subtract the tenths after the decimal point:

93=6 9-3=6

Finally, let's subtract the whole numbers before the decimal point accordingly:

99=0 9-9=0

99=0 9-9=0

00=0 0-0=0

And we get:

100.000099.318000.682 100.000\\-099.318\\000.682

We can ignore the first two zeros and therefore get the number: 0.682

Answer

0.682