Video Transcript
Express the decimal 0.9623 as a percentage.
We’ll consider two possible approaches for answering this question. The first approach involves place value. If we consider the place value of each digit after the decimal point, we can see that the final column in this number is the ten thousandths column. This means that this decimal represents 9623 ten thousandths. We can express it as a fraction: 9623 over 10000.
A percentage is a ratio that compares the number to 100. Percent means out of 100. So in order to work out what this fraction represents as a percentage, we need to write it as an equivalent fraction, where the denominator is 100. We need to find the value of 𝑥 in this equation.
Now, these two fractions must be equivalent. And we can see that to get from 10000 to 100, we must have divided the denominator by 100 as two of the zeros have disappeared. For the two fractions to be equivalent, we must therefore do the same thing to the numerator.
We need to calculate 9623 divided by 100. This is equal to 96.23. The decimal point which would have been at the end of the number moves two places to the left. So if we express the decimal 0.9623 as a fraction with a denominator of 100, it’s equal to 96.23 out of 100. Therefore, as a percentage, it’s equal to 96.23 percent.
There is a second approach that we could have taken, which is to remember a general rule: to convert a decimal to a percentage, multiply by 100. So we multiply the decimal 0.9623 by 100. When multiplying a decimal by 100, the decimal point moves two places to the right.
This of course gives the same answer as the first method: 0.9623 as a percentage is 96.23 percent.
