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# Percents from fraction models

Converting fractions to percentages is a valuable skill in math. To do this, rewrite the fraction with a denominator of 100, as "percent" means "per 100." For example, 7/10 equals 70/100, or 70%. Additionally, you can add percentages together, such as 100% + 80% = 180%.

## Want to join the conversation?

• ik the percent thing but i forget easliy and can get confused so just incase, can sombody explain this in a muck easier way? ;-;
• To change a fraction to a percent, all you have to do is change the denominator of the fraction to 100, and then figure out how you got there. For example, if I have 1/2, and I want to change it to a percent, I can change the denominator to 100, and then divide by my old fraction, aka just dividing 100 by 1/2, and then my answer (50) is my percent. Sorry if I confuse you more.
• no way I got all of them right I think ¯\(ツ)
• what si 20% as a decimal
• To change any percent into a decimal, just divide by 100.
Give it a try.
• At , , , and he tells us to pause the video. Why does he do that?
• so you can learn it and then he explains it and you can check your answer:)
• how many time do you multiply
• It doesn't matter how many times you multiply, just what you multiply.
• What if it's not a square or a rectangle what if its a circle?
• the shape does not matter, as long as you can count the pieces and turn the fraction of that shape and pieces into a fraction over 100, you're good to go!
• how do i take the test for this video without the video saying "not started yet" ?
• wait how do you get the number to multiply by to turn the fraction to a percentage? if this was already said in this video, pls dont mind me I have ADHD. but atleast an answer?
• The idea is to rewrite the fraction as an equivalent fraction with denominator 100.

To do this, figure out what number to multiply the denominator by, to get 100. Then multiply the numerator by the same number.

Example: convert 3/5 to a percent.

First figure out what number to multiply the denominator 5 by, to get 100. Note that 5x2=10, and 10x10 = 100. So 20 is the number we need to multiply 5 by, to get 100.

Now multiply the numerator 3 by 20 to get 60.

So 3/5 = 60/100 = 60%.
The answer is 60%.

Have a blessed, wonderful day!
• this is easier than i thought!
• Why do you have to use 5? Why can't you multiple by 2? 6X2=12 and 20X2=100. Why would this not be an acceptable?
• First, you need to understand the definition of a percent. It is a ratio with a denominator of 100. In this video, Sal is showing you how to convert a fraction into a percentage by forcing the denominator to equal 100.

Please - next time, give a timestamp. This video has multiple problems. I'm assuming you are talking about the problem that starts at about in the video.
Sal starts with a fraction of 6/20. What value can you multiply with 20 to make it into 100? The answer is 5. 5*20 = 100. This is why he is using the 5. He's forcing the denominator to = 100 to match the definition of a percent. Then, to get an equivalent fraction, you also multiply the numerator by 5.

If you look at the other examples in the video, he is doing the same thing. He's forcing the denominator to be 100.
Hope this helps.