Q&A for How to Do Percentages on a Calculator

You can easily calculate your total bill including a tip or a tax by adding 1 to the percentage. For example, if you have a $20 meal and you want to add 15% to the bill, multiply $20 by 1.15 to get $23. That's faster than figuring out 15% of $20, which is $3, then adding it back to $20.

If you have a problem like "What's 25% of 50?" turn the percent into a decimal. In this case, 25% is the same as 0.25. Then, you'd multiply that by the second number—0.25 times 50, which is 12.5.

Multiply 299.00 by 0.06 to get the amount of the discount. Subtract that amount from 299.00 to find the number that replaces 299.00.

If you're asking what percentage 46 is of 164, divide 46 by 164, multiply the quotient by 100, and place a percent sign to the right.

Divide 19 by 29, then multiply the quotient by 100, and add the % mark.

Divide the first number by the second, then multiply by 100 (and add the % mark).

Multiply by 0.15.

Multiply the original pay amount by 0.0205. That gives you the pay increase. Add that to the original pay amount to find the new pay amount.

To convert 2 to a percentage of 4, for example, first divide 2 by 4. The answer is a decimal. Multiply it by 100, then add the percent sign.

Divide the difference (5,064) by the original number (277,088).

Multiply (x/y) by 100. That's the equivalent of (100x) divided by y.

Multiply 754,832 by 0.1. Subtract that number from 754,832.

Divide 213.50 by 0.12.

Divide the amount of the reduction by the original number. Then multiply by 100 to get a percentage value. For example, if 6 is reduced to 4, the amount of the reduction is 2. Divide 2 by the original number, 6. 2÷6 = 0.33. Multiply by 100 to get 33, and add the percent sign: 33%.

No. Those calculations are not equivalent. Full price discounted 17.5% means 100% - 17.5% = 82.5% = 0.825. DiscountPrice = 0.825*FullPrice. But if you divide 1/1.175 on a calculator, you get 0.851, which is a slightly smaller discount (about 15%). Be sure to read these types of problems carefully to answer "percent of what?" Otherwise it's tempting to make a mistake of assuming a 10% increase undoes a 10% decrease, but 1.1*0.90 = 0.99, not 1.00.

Divide 200,000 by 0.51. 200,000 / 0.51 = 392,156.86. That answer makes sense, because 200,000 is slightly more than half (51%) of 392,000.

Enter the bill, then the multiplication sign, then the percentage as a decimal, and finally the "=" sign.

Enter the number, then the multiplication sign ("X"), then the percentage as a decimal. For example, 3% would be entered as ".03", 30% as ".3" and 35% as ".35".

If you want to multiply by 25%, for example, enter the multiplication sign followed by ".25".

Subtract 150 from 320. That's 170. Divide by 150. That's 1.13. Multiply by 100 and add at percent sign. The profit is 113%, diminished by any other costs you might have.

As a decimal, 3.2% is 0.032. 0.032 x 1661.60 = 53.17.