After watching this video lesson, you will be able to convert between percentages, fractions, and decimals easily and quickly. Learn the steps you need to take for each type of conversion.
In math and in the real world, it is important to know how to convert or change between different number formats. It makes your life much easier when you are able to do this. For example, when eating out at a restaurant, if you can easily convert the 20% tip to a decimal that you can multiply with your total, it makes it that much easier for you to calculate the tip that you need to pay.
In this video lesson, you will actually learn several different conversions. We will talk about percentages and fractions, percentages and decimals, and fractions and decimals. Are you ready to begin?
Percentages & Fractions
Okay, so we begin with percentages and fractions. It’s really easy to change from a percentage to a fraction if we remember the definition of percentage. Do you remember what that definition is? The literal meaning of the percent is ‘per one hundred’. So, 50% is simply 50/100. 20% then is 20/100. What do you think 15% is? Now, you might be thinking, hey, these fractions aren’t in simplest form. That’s right! To fully convert from a percentage to a fraction, we need to simplify our fractions. So, 50/100 simplifies to 1/2, and 20/100 simplifies to 1/5.
To go from a fraction to a percentage is a bit more work. First, we need to perform the division, then we can multiply by 100 to get our percentage. So, 1/4 becomes 0.25 after the division of 1 divided by 4. Multiplying by 100 we get 25, so our percentage here is 25%. Let’s try another one. 1/5 turns into 0.2. Multiplying by 100 we get 20, so 1/5 is 20%.
Percentages & Decimals
Now, let’s look at percentages and decimals. To go from one to the other is simple for both ways. All we have to do is move the decimal point. Yes, that’s right. That’s how easy it is. Either way, we move the decimal point two spaces. Remember how we had to multiply our fraction-turned-decimal by 100 to get our percentage? This actually moves our decimal two spaces to the right. So, converting from a decimal to a percent, we move the decimal point two spaces to the right. For example, 0.87 becomes 87%. The decimal point simply moved two spaces to the right.
What do you think we do to convert from a percentage to a decimal? We move our decimal two spaces to the left. So, 34% becomes 0.34. Our decimal moved two spaces to the left.
Fractions ; Decimals
Lastly, let’s talk about fractions and decimals. This actually involves all the skills we just talked about. For this part, the easy part is converting from a fraction to a decimal. To do this, we simply divide. If we see 2/5, we divide 2 by 5. What do we get? We get 0.4.
To convert from a decimal to a fraction requires a bit more work. To do this conversion, we first have to count how many decimal places we have. This tells us how to convert our decimal into a fraction. If we have one decimal place, then we divide by 10. For example, to convert 0.2 to a fraction, we take our number without the decimal and divide by 10: 2/10, which simplifies to 1/5. We have one zero for every decimal place we have. To convert 0.25 to a fraction, we divide it by 100. Because we have two decimal places, we divide it by a 1 followed by 2 zeroes. So, we have 25/100, which simplifies to 1/4.
Let’s review what we’ve learned now:
To convert means to change. To convert from a percentage to a fraction, we simply place our percentage number over 100 and simplify. To convert from a fraction to a percentage, we perform the division and then multiply by 100. To convert a percentage to a decimal, we move the decimal point two places to the left. To convert a decimal to a percentage, we move the decimal point two places to the right. To convert a fraction to a decimal, we perform the division. To convert a decimal to a fraction, we take our decimal number without the decimal point and place it over a 1 followed the same number of zeroes as we have decimal places and then simplify.
You should be able to convert between fractions, decimals and percentages after reviewing this lesson.