Last updated on June 11th, 2025
Percent proportion is used to solve problems involving percentages. It is an equation where a percentage (%) of the whole number is equal to a part of the whole. In this topic, we are going to learn more about percent proportions.
In math, percent proportion is an equation that shows how a percentage is related to a whole number. We mainly use it to determine an unknown value, whether it is the part, the whole number, or the percentage.
When a student scores 45 marks out of 60 in a test, and we need to find the percentage of the score, we would use percent proportion to find out the percentage of the score.
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To calculate percent proportion, we use the formula:
Part/whole = Percent/100
Where,
Part is the portion of the total ( e.g. marks obtained in a test)
Whole is the original amount ( e.g. total marks for a test)
Percent is the percentage given in a problem (out of 100)
For example, 40 is what percentage of 90?
The first thing to do is identify the key terms “IS” and “OF”.
IS: It is the part we are looking at, in this case 40.
OF: It is the whole amount; in this example, it is 90.
So with this information, let's substitute the values.
Part/whole = Percent/100
Now we need to cross multiply,
40 × 100 = 90 × whole
4000 = 90 × whole
4000 / 90 = 44.444%
Whole = 44.444%
Percent proportion follows certain mathematical properties to help in solving any kind of percentage-related problem. Here are some key properties:
Percent proportion allows us to easily compare different quantities, because of which it is used as a tool to understand and interpret data in real-life situations. It also helps solve problems that include percentages.
With the right approach, it is easy to master percent proportion. Here are some useful tips and tricks to help students quickly and accurately master percent proportion
Percent proportion is used in many real-life situations like calculating discounts, decision-making, and analyzing different trends. Here are a few real-life situations that we come across every day.
Percent proportion is important because it helps in simplifying percentage problems. However, students can often make quite a few mistakes while solving problems. Here are some common mistakes that students sometimes make
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What number is 13% of 400?
52
Using the percent proportion formula,
x/400 = 13/100
Cross multiply:
100x = 13 × 400
100x = 5200
x = 5200/100 = 52
Using percent proportion formula, 30 is 60% of what number?
50
Using the formula,
30/x = 60/100
Cross multiply:
60x = 30 × 100
60x = 3000
x = 3000/60 = 50
What number is 70% of 800?
560
x/800 = 70/100
Cross multiply:
100x = 70 × 800
100x = 56000
x = 56000/100 = 560
What number is 35% of 350?
122.5
x/350 = 35/100
Cross multiply:
100x = 35 × 350
100x = 12250
x = 12250/100 = 122.5
Using percent proportion formula: 65 is 30% of what number?
216.67
65/x = 30/100
Cross multiply:
30x = 65 × 100
30x = 6500
x = 6500/30 = 216.67
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Dr. Sarita Tiwari is a passionate educator specializing in Commercial Math, Vedic Math, and Abacus, with a mission to make numbers magical for young learners. With 8+ years of teaching experience and a Ph.D. in Business Economics, she blends academic rigo
: She believes math is like music—once you understand the rhythm, everything just flows!