When you’re setting up two proportions, it’s easiest to set them both up as the part over the whole on either side of the equation. [5] X Expert Source Jake AdamsAcademic Tutor & Test Prep Specialist Expert Interview. 24 July 2020.

There are 12 months total in a year, so Jerry worked 7/12 months. Then, convert the fraction to a decimal: 7/12 = 0. 58 Next, convert the fraction to a percent: 0. 58 x 100% = 58% Jerry the electrician worked 58% of the year.

35 correct answers + 10 incorrect answers = 45 answers total We can set this problem up as the fraction 35/45. 35/45 = 0. 78 0. 78 x 100 = 78% Donovan got 78% of the answers correct on his test.

Remember, part over whole equals part over whole. [13] X Expert Source Jake AdamsAcademic Tutor & Test Prep Specialist Expert Interview. 20 May 2020.

You can translate any percentage into a decimal by dividing by 100. For example, 26% = 26/100 = . 26[15] X Expert Source Jake AdamsAcademic Tutor & Test Prep Specialist Expert Interview. 24 July 2020.

In this example, $0. 45 is the amount of interest accrued each day that you do not pay your friend back. If you need to further calculate the total due after 1 day, you would add the amount you borrowed to the amount of the interest times the number of days. So $15 + ($0. 45 x 1 day) = $15. 45.

We can reword this problem as “What is 80% of 35?” Plug the values into the formula P/100 = Part/Whole 80/100 = X/35 0. 8 = X/35 35 x 0. 8 = X X = 28 The pitcher won 28 games.

We can reword this problem as “What is 93% of 8. 15?” Plug the values into the formula P/100 = Part/Whole 93/100 = X/8. 15 0. 93 = X/8. 15 0. 93 x 8. 15 = X X = 7. 58 There are 7. 58 ounces of silver.

A shortcut: notice you can manipulate the percent equation to get this formula below. Part/Percent (in decimal form) = Whole Keep reading for a full walk-through if you’re not sure how to get there.

Bonus Example 1: This year, Acme Computers made approximately 72% of its sales online. There were 1,380 online purchases. Rounding up to the nearest whole number, how many total sales did Acme Computers make this year? Plug the values into the formula P/100 = Part/Whole 72/100 = 1,380 online sales/Y total sales 72/100 = 1,380/Y 0. 72 = 1,380/Y 0. 72 x Y = 1,380 1,380/0. 72 = Y Y = 1916. 66 Acme Computers made 1917 total sales this year. Bonus Example 2: 39% of what number is 89? Plug the values into the formula P/100 = Part/Whole 39/100 = 89/Y 0. 39 = 89/Y 0. 39 x Y = 89 89/0. 39 = Y Y = 228. 2

New Amount - Original Amount = Difference $15. 75 - $13. 99 = $1. 76 (Difference / Original Amount) x 100% = Percent Increase ($1. 76 / $13. 99) x 100% = 12. 5% The price of the game went up by 12. 5%.

New Amount - Original Amount = Difference $55 - $22 = $33 (Difference / Original Amount) x 100% = Percent Increase ($33 / $55) x 100% = 60% The company has a 60% markup on sweaters.

Original Amount - New Amount = Difference 42 - 39 = 3 (Difference / Original Amount) x 100% = Percent Increase (3 / 42) x 100% = 7% Jane’s hours decreased by 7%.

Original Amount - New Amount = Difference 563 - 542 = 21 (Difference / Original Amount) x 100% = Percent Increase (21 / 563) x 100% = 3. 7% Company A decreased their number of employees by 3. 7%.

Calculating a 10% tip: Simply move the decimal place over once to the left. Example: If your bill is $54, a 10% tip would be $5. 4. Calculating a 15% tip: Find 10% by moving the decimal place over to the left. Then, divide that number in half to get 5% of the bill. Then, add the 10% and 5% values together. Example: For a $54 bill, 10% is $5. 4. Half of $5. 4 is $2. 7. Finally, $5. 4 + $2. 7 = $8. 1. Calculating a 20% tip: Double the total bill, then move the decimal place over once to the left. Example: For a $54 bill, double that is $108. If you move the decimal one place to the left, you’ll get $10. 80.

Move the decimal two places to the left. In this example, 70%/100% = 70/100 = 7/10 = 0. 7. [28] X Research source Multiply the original price by the new decimal. If the shirt you want is $20, multiply $20 by 0. 7. This comes to $14, meaning the shirt is now on sale for $14. [29] X Research source Calculate your savings. Simply subtract the sale price from the original price ($20 - $14 = $6 saved)!

Bonus Example: Mark is buying a sweater that costs $15. Sales tax is 9%. How much will he pay at checkout? Convert 9% to a decimal: 0. 09 Add the decimal to 1: 0. 09 + 1 = 1. 09 Multiple that value by the original price: $15 x 1. 09 = $16. 35 Mark will pay $16. 35 at checkout.