How to Figure Out What Number 90 is 50% Of

Understanding Percentages: How to Figure Out What Number 90 is 50% of

Percentages are used every day to represent fractions and proportions. For example, if you see something is 50% off during a sale, you know it's now half the original price. To determine what number 90 is 50% of, you need to understand the relationship between percentages, fractions and whole numbers. Let's walk through the steps to figure out this math problem.

Reviewing Fractions

A fraction represents a part of a whole. The top number (numerator) is the number of parts you have, and the bottom number (denominator) is the total number of parts.

For example, the fraction 2/4 means you have 2 parts out of 4 total parts. Fractions that have the same numerator and denominator, like 2/2, represent the whole (100%).

Converting Fractions to Percentages

A percentage is just a fraction with a denominator of 100. To turn a fraction into a percentage, you divide the numerator by the denominator and multiply by 100.

For example, if you have a fraction of 1/2, divide 1 by 2 to get 0.5. Then multiply 0.5 by 100 to get 50%.

So the fraction 1/2 = 0.5 = 50%.

Understanding the Percent Equation

There is a reliable formula for determining what percentage one number is of another number:

Percentage = Part/Whole x 100

If you know the percentage and the part, you can plug those values into the formula to solve for the whole number.

Figuring Out What Number 90 is 50% of

Now let's apply this understanding of percentages and the percent equation to the original question: What number is 90 50% of?

We know:

The percentage is 50%
The part is 90

We want to find:

The whole number

Plugging this into the percent equation:

50% = 90/Whole x 100

Now we isolate the unknown variable - the whole number:

50/100 = 90/Whole

1/2 = 90/Whole

2 = 180/Whole

Whole = 180

The Solution

Using the percent equation, we determined that 90 is 50% of 180. If you take 180 and divide it in half, you get 90.

To double check, we can take 90 and divide by the percentage (50% or 0.5) to get 180.

So 90 is 50% of 180.

Using the Percent Equation to Solve Other Percent Problems

Now that you understand how to use the percent equation, let's practice applying it to other example percentage problems:

Problem 1

25 is 10% of what number?

Percentage = 10% Part = 25 Whole = ?

Plugging into equation: 10% = 25/Whole x 100 0.10 = 25/Whole Whole = 250

Therefore, 25 is 10% of 250.

Problem 2

What number is 30% of 60?

Percentage = 30% Part = ? Whole = 60

Plugging into equation: 30% = Part/60 x 100 0.30 = Part/60 0.30 * 60 = Part Part = 18

Therefore, 30% of 60 is 18.

Problem 3

20 is 25% of what number?

Percentage = 25% Part = 20 Whole = ?

Plugging into equation: 25% = 20/Whole x 100 0.25 = 20/Whole Whole = 80

Therefore, 20 is 25% of 80.

Tips for Solving Percent Word Problems

Here are some helpful strategies for tackling other types of percent word problems:

Draw a visual fraction to represent the percentages.
Define the known (given) and unknown (missing) variables.
Set up a percent equation and isolate the variable you want to solve for.
Think logically about which number should be bigger or smaller.
Check your solution by plugging it back into the original word problem.

Applying Percentages to Real Life Situations

Understanding percentages is an important life skill with many practical applications:

Calculating discounts, taxes, tips, commissions, interest rates
Comparing nutritional information on food labels
Analyzing statistics and data
Converting between fractions, decimals and percentages
Scaling recipes up or down

Anytime you need to find or represent a part of a whole, percentages likely come into play. Brushing up on how to solve problems like determining what number 90 is 50% of will help boost your math abilities for daily life.

FAQs

How do you convert a fraction to a percentage?

To convert a fraction to a percentage, divide the numerator by the denominator and multiply by 100. For example, 1/2 = 0.5 = 50%.

What is the percent equation?

The percent equation is: Percentage = Part/Whole x 100. You can use this formula to find an unknown part, whole, or percentage.

What are some tips for solving percent word problems?

Tips include: drawing a visual fraction, defining known vs unknown variables, setting up an equation, thinking logically, and checking your solution.

When are percentages used in real life?

Percentages are used often in real life for calculating discounts, nutrition info, statistics, converting fractions, scaling recipes, and finding parts of wholes.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.