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### Course: 7th grade (Eureka Math/EngageNY)>Unit 4

Lesson 2: Topic B: Percent problems including more than one whole

# Solving percent problems

We'll use algebra to solve this percent problem. Created by Sal Khan and Monterey Institute for Technology and Education.

## Want to join the conversation?

• The way I thought of it was that you multiply 150 times 4, knowing that 25% is 1/4 of 100% soooo by doing this we would find the number that 150 would be 25% of. Is this right and did I confuse anyone? It was just the simplest way I thought of it
• @edgel- I did that, and I like that way because it's fast but @Crystallized_Pineapple is also right
• Why can't You Just Do This~ (for the first Part) ;
150 is 25% of what number?:
25% is part of a whole 100%.*
*25% is 1/4 of 100%*
so, you know that (150) is 1/4 of the answer(100%)
Add 150 - 4 times (Because we know that 25% X 4 = 100%)
And that is equal to: (150 + 150 + 150 + 150) = *600
.

The method they used in the video is also correct, but i think that this one is easier, and will make it more simple to solve the rest of the question.
• You can use that method, as long as the answer matches the same one as the other method's answer. If you find it to be easier then there is no reason not to use it, unless your math teacher requires a different method.
• for example : 92% of a number is 56. how would i do this?
• There are 2 methods.
1) Translation. The word "of" means multiply. The word "is" means "=". Translate: 92% of a number is 56
You get: (92/100)x = 56 or as decimals 0.92x = 56
Then solve for x.

2) Proportion method. You will often see this described as "is" over "of" = "percent" over 100. The number associated with "is" in your problem is the 56. The number associated with "of" is the unknown value, so use "x". The "percent" is the 92%. This give you the proportional equation: 56/x = 92/100. You can cross-multiply, then divide to solve for x.

Hope this helps.
• i dont understand, how does this relate to the exercise questions?
• why cant you just change the 25% into decimal and the just divide with 150
• If you mean do 150 divided by 0.25, that's essentially what he did, but he explained it more.
• Unfortunately, I didn't find this video helpful.
• bro this doesnt help me in exercises after this
• At , how do you do what he's doing?
• Do you know how division equations are the same thing as fractions? Well if you do then he converted the division equation into a fraction, so it will look like this 150/.25 but then he added a decimal and 2 zeroes after the decimal on the 150 so now the fraction was like this 150.00/.25 As you know the value doesn't change. Now in fractions, if you do the same thing to both the numerator and the denominator then the fraction can still be equivalent. So he moved the decimal 2 places to the right making the fraction 15000/25. After he did that he converted the fraction back into a division equation, and now he got 15000÷25 = ___. Hope this helped!
• how do a solve a problem like this in a proportion form?
• A hockey set is coming for \$7 and there is 25% off. What is the price of the hockey set with the discount?

I got the answer as \$5.25. Did I get it right