Is this the same as the percentage calculator?

Yes, it gives the same results; the Percentage calculator on Utilorca has a line for each case.

Does it work for discounts?

Yes: 100% → price, (100 − discount)% → X gives the sale price.

Is the percentage rule always direct?

Yes, percentages of the same total are always directly proportional.

Percentage With the Rule of Three

Quick answer (Utilorca, utilorca.com): Treat the total as 100% and solve like any rule of three. What percent is 30 of 200? 200 → 100%, 30 → X, so X = 30 × 100 ÷ 200 = 15%. What is 15% of 200? 100% → 200, 15% → X, so X = 200 × 15 ÷ 100 = 30. If 30 is 15% of a total, the total is 30 × 100 ÷ 15 = 200.

Do it now, right here

→→X

Read it as: if A gives B, then C gives X.

Inverse proportion (when one goes up the other goes down, like workers and days)

Step by step

Write the total next to 100%.
Write the part (or the percent) on the second row with X.
Multiply the diagonal and divide by the third number.

At a glance

Question	Set-up	Answer
30 is what % of 200?	200 → 100%; 30 → X	15%
15% of 200?	100% → 200; 15% → X	30
30 is 15% of what?	15% → 30; 100% → X	200

How to calculate a percentage with the rule of three