Percent Proportions

Percent Proportion

How to work with problems that include percentages.

The Percent Proportion

This set-up can be used to solve ANY percentage problem that gives you 2 numbers (the 100 is automatically input).

What is 25% of 300?

The 25 has a % sign, so it goes above the 100.

The 300 has OF in front, so it goes on the bottom left.

What is 25% of 300?

Next, we cross-multiply the numbers diagonal from each other.

300 x 25 = 7500

And then divide by the last number (does not have someone diagonal to it).

7500 / 100

Two steps; Multiply and Divide to get your answer ... 75

Multiple Choice

What is 33% of 187

• 17.6

• 61.71

• 566.67

• 75.21

What percent of 80 is 32?

The 80 has an OF in front of it (it does have an is behind it...but that covers the NEXT number!)

The 32 has an IS in front.

Hint: The question says WHAT percent...so we are looking for the %!

What percent of 80 is 32?

Multiply the 32 and 100 since they are diagonal

32 x 100 = 3200

The 80 has no one diagonal to it, so divide by 80.

3200 / 80 = 40

That means that 40% would be your answer (remember to include the % sign when that is what you are looking for!)

Multiple Choice

What percent of 45 is 37?

• 82

• 17

• 122

• 91

18 is 300% of what?

The 18 has nothing in front, but says IS afterward, so it goes on the top left.

The 300 has a %, so it goes on the top right.

This time it says OF what...so we are looking for the of.

Also...notice how BIG the % is? Don't get freaked...you can have over 100%!

18 is 300% of what?

The 18 and 100 are diagonal so multiply them.

18 x 100 = 1800

The 300 does not have a diagonal, so divide by it.

1800 / 300 = 6

This means your answer is 6, which makes sense since 300% is MORE than what you started with and 18 is more than 6!

Multiple Choice

164.9 is 170% of what?

• 54.2

• 97

• 280.33

• 500

Part of a Whole Amount

So far, Tyler ran 9 laps, which was 75% of his total run. How many laps is Tyler's run?

This problem has no IS or OF, but you can use the PART he ran compared to the WHOLE amount!

Part of a Whole Amount

Tyler ran 9 laps, which was 75% of his total run. How many laps was Tyler's run?

The 75% goes in the percent section.

The 9 laps is NOT the whole run, so it goes in the IS or PART section.

We are trying to find how many laps he should run...so the WHOLE!

Part of a Whole Amount

Tyler ran 9 laps, which was 75% of his total run. How many laps was Tyler's run?

Now multiply the 9 and 100 since they are diagonal from each other.

9 x 100 = 900

Then divide bly the 75 since it is alone.

900 / 75 = 12

His total run should be 12 laps!

Multiple Choice

Ashley drove 6.9 miles, which was 16% of her trip. How many miles will her trip take?

• 1.1

• 6.9

• 43.1

• 112.4

Practice Time

Multiple Choice

15 is 75% of what

• 5

• 20

• 45

• 100

Multiple Choice

35 is what percent of 700?

• 5

• 15

• 55

• 105

Multiple Choice

48 is 80% of what?

• 40

• 60

• 80

• 100

Multiple Choice

What is 12% of 17.5?

• 2.1

• 4.2

• 8.4

• 16.8

Multiple Choice

Johnny paid $9,000 towards a down payment for his new car. This was 60% of the total value.

How much was the car?

• $5,000

• $9,000

• $15,000

• $22,000

Multiple Choice

The regular price of a TV is $475. It’s currently on sale for 20% off.

What is the discount if you bought the TV during the sale?

• $95

• $380

• $570