If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## MAP Recommended Practice

### Course: MAP Recommended Practice>Unit 17

Lesson 8: Percent problems

# Percent of a whole number

Discover how to calculate percentages with a simple example: finding 30% of 6. Learn two methods, using fractions and decimals, to solve this problem. Both approaches lead to the same result, showing that 30% of 6 equals 1.8. Master these techniques for everyday calculations. Created by Sal Khan.

## Want to join the conversation?

• At , how do you turn the improper fraction into a mixed number? •  you can turn an improper fraction to a mixed number by dividing the top number by the bottom number and that is how you do it :)
• I don't understand how Sal turned the fraction into a decimal. How is 4/5 related to 4 divided by 5? (At ) • at a scale of 500 percent a measurment is 165mm. what is the actual size? • The video teaches how to find a percentage of a number, here you're given the percentage and looking for the original number, so you should reverse the operation, and do division.

What is the number when multiplied by 500/100 (that's 500%) gives 165?
? x 500/100 = 165

You can divide 165 by 500/100 to find the answer, or since we're dividing by a fraction, you can just multiply by its reverse, so it becomes likes this:
165 x 100/500 = ?
(165 x 100) / 500 = 16500 / 500
16500 / 500 = 33

The original number should be 33.
• Why make these things so complex? I will just divide 6 by 100. And then multiply by 30.
6/100=0.06
0.06*30=1.8

simple as that. • Here's what I did so maybe it will help you guys.
(Please don't say I'm getting this off of AI, 'cause im not, I just did some random multiplying and converting and when I put my answer is was correct every time. Im saying this because this has happened before.)
______________

So this is one of the questions in the exercises you have to do. These question come from the "Benchmark percents" exercise.

What is 1% of 800? (Fact! The "of" in 1% of 800, mean "times" (x) in math, so it really translates: What is 1% x 800?)
__________

First we convert.
1% = 1/100

Then we divide:
1 ÷ 100 = 0.01

Now we can get back to the original question; What is 1% of 800?

Multiply 0.01 by 800;
0.01 x 800 = 8!

So 1% of 800 (1% x 800) = 8!

__________________

This question comes from the "Equivalent representations of percent problems" exercise.
_______

Which of the following options have the same value as 62% of 45? Chose 2 answers:

a) 0.62 x 45
b) 45 ÷ 0.62
c) 62/100 x 45
d) 62 ÷ 45
e) 62 x 45
_______________

Now this is just like the first question but asking us what equation is for the correct value of the question "Which of the following options have the same value as 62% of 45?"

So lets just solve the equation 62% of 45.

Convert:
62% = 62/100- WAIT you could stop right here and do 62/100 x 45 instead of converting 62/100 to a decimal.

Which option has 62/100 x 45? Option c) does. So c) is one of our answers. And we can check.

Lets finish our work.
62% = 62/100

62 ÷ 100 = 0.62

0.62 x 45 = 27.9

Now check to see if 60/100 x 45 has the same answer as 27.9.

62/100 x 45 = 27.9!!

So c) 62/100 x 45 is one correct answer.

Now we need one more answer since the question asks for 2.

Lets review our options.

a) 0.62 x 45
b) 45 ÷ 0.62
c) 62/100 x 45 CORRECT
d) 62 ÷ 45
e) 62 x 45

Okay so we 4 more left now we could just enter every question into a calculator to see if it would equal 27.9. But there's a faster and better way to go about this.

Back when we were answering the question 62% of 45 there was a moment we had the number 0.62. And we were multiplying it by 45.
(0.62 x 45)
That equation is in one of our options. Which one has "0.62 x 45"? option a) does. And we don't even have to check it. We literally did it under the phrase I wrote "Lets finish our work."

0.62 x 45 does = 27.9

So our answers to the question "Which of the following options have the same value as 62% of 45" is option c) and a).
a) 0.62 x 45 CORRECT
b) 45 ÷ 0.62
c) 62/100 x 45 CORRECT
d) 62 ÷ 45
e) 62 x 45

If you guys want be to talk about the last exercise in khan academy which is called "Finding percents". Upvote this please! • These comments are very old!
Not to waste your time reading this, but if i did waste your time I'm so sorry • The video teaches how to find a percentage of a number, here you're given the percentage and looking for the original number, so you should reverse the operation, and do division.

What is the number when multiplied by 500/100 (that's 500%) gives 165?
? x 500/100 = 165

You can divide 165 by 500/100 to find the answer, or since we're dividing by a fraction, you can just multiply by its reverse, so it becomes likes this:
165 x 100/500 = ?
165 x 100 = 16500
16500 / 500 = 33

The original number should be 33.
It will help you to understand...if you could then hit a like 👍🏻👍🏻 • this is too quick can someone explain it to me? • So basically 50% of 100 is 50, and 50% of 5 is 2.5, if you get fractions and decimals then this is easy.
Here is a method to make calculating percentages easier.
Graph paper or any paper recommended
Let's say I want to find 80% of 200, then I would write 200 x 80 (over 100)= ?. The two 0s from the 80 over 100 and 200 cancel out each other. 80 * 2= 160, so 160 is 80% of 200.
Hope this helps  