Percents
Every lesson explains the concept, works through examples, and gives you practice problems with full solutions. Work through them in order, or jump to the topic you need.
7 lessons
- What Is a Percent? Percents, Fractions and DecimalsWhat percent means, why it is out of one hundred, and how to move between a percent, a fraction and a decimal without memorising three separate rules.
- How to Find a Percent of a NumberThree ways to find a percent of a number: convert to a decimal and multiply, use a fraction, or build it from 10% and 1% in your head.
- What Percent Is One Number of Another?How to find what percent one number is of another: divide the part by the whole and multiply by 100, and how to tell which number is the whole.
- Percent Increase and DecreaseHow to find a percent increase or decrease, why the change is always measured against the original, and how to apply one in a single multiplication.
- Discounts, Sales Tax and TipsHow to work out a sale price, add sales tax, and calculate a tip, using one multiplication instead of two steps — and why the order does not matter.
- Simple Interest: The Formula and What Each Letter MeansHow to use I = Prt to find simple interest, how to rearrange it for any missing letter, and why simple interest differs from compound interest.
- Percent Word Problems: Which of the Three Questions Is It?Every percent word problem is one of three questions. How to tell which you have been asked, and how to solve each one, with worked examples.