Calculating 20% of 90: A Quick How-To Guide

Have you ever found yourself needing to quickly figure out what is 20 of 90? Whether you’re splitting a restaurant bill, calculating a tip, or determining a discount on a purchase, knowing how to easily find 20% of 90 is a valuable skill. Let’s walk through how to solve this common math problem step-by-step.

Breaking Down the Calculation

To find 20 percent of 90, we’ll use a simple formula. In general terms, here’s how it works:

[Percentage] x [Number] = [Result]

In this case, our percentage is 20% and our number is 90. So plugging those into the formula, we get:

20% x 90 = Result

Converting the Percentage to a Decimal

The first step is to convert 20% to a decimal. To do this, simply move the decimal point in 20 two spaces to the left, which gives us 0.20.

So now our formula looks like this:

0.20 x 90 = Result

Multiplying the Decimal by the Number

Now that we have our percentage as a decimal, we can multiply it by our original number, 90. Let’s solve the equation:

0.20 x 90 = 18

And there we have it – 20% of 90 equals 18. So if you’re at a restaurant and your bill is $90, a 20 percent tip would be $18. Or if an item normally costs $90 but is 20% off, you’ll save $18.

A Few More Examples and Tips

Once you understand the basic formula for finding a percentage of a number, you can use it for all sorts of applications. Need to calculate 15% of 50? Simply convert 15% to 0.15 and multiply it by 50 to get 7.5.

Want to find 7.5% of 160? Change 7.5% to 0.075 and multiply it by 160 for a result of 12. With a little practice, you’ll soon be able to quickly estimate percentages in your head.

Percentages come up surprisingly often in daily life. Sales tax, interest rates, poll results – knowing how to find a percentage of a given number lets you make sense of them all. So the next time you see a statistic like “37% of people prefer chocolate ice cream,” you’ll be able to easily figure out how many people that actually represents based on the sample size.

Exploring the Concept Further

Figuring out what 20% of 90 is may seem like basic math, but it opens the door to more complex concepts. Once you’re comfortable calculating percentages, you can start to understand ideas like percentage change over time, or even use algebraic equations to find the original number when given a percentage and result.

But for most everyday situations, simply remembering the formula Percentage x Number = Result will let you find what is 20 of 90 or any other percentage problem that comes your way. With this handy skill in your mathematical toolkit, you’ll be able to quickly calculate discounts, taxes, and tips – impressing your friends and making numbers just a little less intimidating.

So go ahead, embrace your inner math whiz. The next time you encounter a percentage in the wild, you’ll know exactly what to do. Happy calculating!

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