Converting Decimals to Percents

We already know that "percent" means per hundred.

Using this we can easily convert a decimal to a percent.

Example 1. Convert 0.34 to percents.

Recall that $$${p}\%=\frac{{p}}{{100}}$$$.

So, what we want is to convert decimal into fraction, whose denominator equals 100.

Using equivalence of fractions we can write that $$${0.34}=\frac{{{0.34}}}{{1}}=\frac{{{0.34}\cdot{100}}}{{100}}=\frac{{{\color{red}{{{34}}}}}}{{100}}$$$.

Answer: 34%.

Next example.

Example 2. Convert 8.357 to percents.

Just like in example 1 $$${8.357}=\frac{{{8.357}}}{{1}}=\frac{{{8.357}\cdot{100}}}{{100}}=\frac{{{\color{red}{{{835.7}}}}}}{{100}}$$$.

Answer: 835.7%.

Next example shows a bit easier way of converting.

Example 3. Convert 41.5758 to percents.

From previous two examples it is clear that we need to multiply decimal by 100 to get percent.

But multiplying by 100 is equivalent to moving the decimal point two places to the right:

41.5758 becomes 4157.58%.

Answer: 4157.58%.

Last example shows how to correctly move decimal point when there are not enough digits in the decimal part.

Example 4. Convert 3.5 to percents.

We need to move decimal point to the right, but there is only one digit in the decimal part.

No problem. Recall, that you can add to decimal part as much trailing zeros as you want. We need only one.

So, 3.5 becomes 3.50. Now, you can move decimal point: 3.50 becomes 350.

Answer: 350%.

Let's summarize it.

To convert decimal to percents multiply decimal by 100 or, equivalently, move decimal point two places to the right.

Now, it is time to practice.

Exercise 1. Convert 0.12 to percents.

Answer: 12%.

Next exercise.

Exercise 2. Convert 5.789 to percents.

Answer: 578.9%.

Next exercise.

Exercise 3. Convert 45.5 to percents.

Answer: 4550%.

Next exercise.

Exercise 4. Convert 17 to percents.

Answer: 1700%.