How do you work out percentages on a simple calculator?

Answer 1

With Calculator - If something is 4/5, you first divide 4 by 5. You should get '.8' You then just move the decimal two places to the right, getting you 80. Then you just add the % symbol to get 80%.

Answer 2

Answer #1:

You have to remember that "percent" means "as a part of 100"; i.e. any percentage is simply that amount as a fraction of 100. For example 20% is 20/100 or 0.20, 68% is 68/100 or 0.68, 437% is 437/100 or 4.37, and so on. The digits are the same but the decimal point is moved left or right two spaces. In other words:

• A percentage is simply the decimal number multiplied by 100
• A decimal number is simply the percentage divided by 100.

If you remember those rules, working out percentages on a calculator is easy!

Example 1: What is 3/8 as a percentage? (or, 3 is what percent of 8?)

Dividing 8 into 3 on your calculator gives you 0.375 as a decimal. Because a percentage is a decimal multiplied by 100, multiply by 100 (i.e. move the decimal point two spaces to the right): 0.375 = 37.5%

Example 2: What is 65% of 14?

You need to convert 65% to a decimal number. Because a decimal is a percentage divided by 100, move the decimal point two spaces to the left: 65% = 0.65. Then you can enter 0.65*14 on the calculator to get an answer of 9.1

You can also use the percentage-to-decimal rules to quickly compute taxes and discounts on a calculator. If you do that, most ordinary problems involving taxes and discounts simplify down to adding or subtracting a percentage from 1, then multiplying:

Example 3: A shirt costs 35.99 and the sales tax is 8%. What is the total cost?

As a decimal, the sales tax is 0.08 (8/100) so the tax amount is 0.08*35.99. Now you could calculate that separately and add it to the shirt's original price ... but if you think about it for a minute, the final price is the original price, or 1 times the price, plus the tax, or 0.08 times the price. That means the final price is (1 + 0.08), or 1.08, times the original price: 1.08 * 35.99 = 38.87, rounded to the next penny.

In other words, to figure out a total price with tax: Convert the tax to a decimal, add it to 1, and multiply by the original price.

Example 4: A TV normally costs 425.50 and is on sale at 25% off. What is the sale price?

Like the problem with the shirt, you could calculate the discount separately, then subtract from the original price ... but again, you can think of the calculation as 1 times the original price minus the discount of 0.25 (25%) times the original price. That means the sale price is (1 - 0.25), or 0.75, times the original price: 0.75 * 425.50 = 319.13, rounded to the next penny.

In other words, to figure out a sale price with discount: Convert the discount to a decimal, subtract it from 1, and multiply by the original price.

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Answer #2:

It depends on what you start with.

If you are given the problem: "X is what percentage of Y?"

X [divided by] Y x 100 = Percentage

If you are given the problem: "What is X percent of Y?"

Y x (X [divided by] 100) = Number

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Answer #3:

A calculator can't help you if you don't know the math.

You have to know that 'percent' means " .../100 ".

Answer 3

To find 50% of 400: 50 ÷ 100 × 400 = 200

Another method: .50 × 400 = 200

Then simply add a percentage sign (200%) to show that the answer is a percentage and not an integer. A percentage symbol on a calculator is not essential!

Answer 4

A number X, as a percentage of another number Y is 100*X/Y.