Percentages Master Guide ๐
Master percentage definitions, FDP conversions, finding percentage of amounts, reverse percentages, and bar model word problems for 11+ exams!
PERCENTAGES OVERVIEW
A percentage means "out of 100". We write it using the % symbol. ($25\% = \frac25100 = 0.25$)
A percentage shows a part of a whole "out of 100". The whole is 100%.
Percentages, fractions and decimals can show the same value.
| Percentage | Fraction | Decimal |
|---|---|---|
| 1% | 1/100 | 0.01 |
| 5% | 5/100 or 1/20 | 0.05 |
| 10% | 10/100 or 1/10 | 0.10 |
| 25% | 25/100 or 1/4 | 0.25 |
| 50% | 50/100 or 1/2 | 0.50 |
| 75% | 75/100 or 3/4 | 0.75 |
| 100% | 100/100 or 1 | 1.00 |
Percentages can be shown in different visual ways.
Different percentages and fractions can be equivalent.
Percentages can be more than 100%. (150% means 150 out of 100 = 1.5)
EQUIVALENT FRACTIONS, DECIMALS & PERCENTAGES
Different ways to show the same value. Fractions, decimals and percentages are equivalent.
- โ Equivalent means equal in value.
- โ Size is the same, just written differently.
- โ You can convert between all three!
| FRACTION | DECIMAL | PERCENTAGE |
|---|---|---|
1/4 | 0.25 | 25% 25% 25% 25% 25% |
1/2 | 0.50 | 50% 25% 25% 25% 25% |
3/4 | 0.75 | 75% 25% 25% 25% 25% |
1/1 | 1.00 | 100% 25% 25% 25% 25% |
1/5 | 0.20 | 20% 25% 25% 25% 25% |
2/5 | 0.40 | 40% 25% 25% 25% 25% |
3/5 | 0.60 | 60% 25% 25% 25% 25% |
4/5 | 0.80 | 80% 25% 25% 25% 25% |
1/8 | 0.125 | 12.5% 25% 25% 25% 25% |
3/8 | 0.375 | 37.5% 25% 25% 25% 25% |
5/8 | 0.625 | 62.5% 25% 25% 25% 25% |
7/8 | 0.875 | 87.5% 25% 25% 25% 25% |
1/10 | 0.10 | 10% 25% 25% 25% 25% |
1. Divide numerator by denominator.
1. Multiply decimal by 100.
1. Divide percentage by 100.
1. Write percentage over 100.
2. Simplify the fraction.
โ All three show the exact same amount!
โ It's just a different way of writing it!
Hover over any grid to see its percentage representation!
PERCENTAGE WORD PROBLEMS USING BAR MODELS
Bar models help us understand percentage problems by showing the whole as 100% and parts as equal sections.
Q: 25% of a number is 30. What is the number?
25% is 1/4 of the whole. If 25% = 30, then 100% = 30 ร 4 = 120.
Q: 60% of a number is 72. What is the number?
60% is 6 lots of 10%. 72 รท 6 = 12 (one lot of 10%). 100% = 12 ร 10 = 120.
Q: A bag has 80 sweets. 30% of the sweets are red. How many are red?
10% of 80 = 8. 30% = 3 lots of 10% = 8 ร 3 = 24 sweets.
Q: In a class of 40 students, 16 students like pizza. What percentage likes pizza?
Each 10% block = 40 รท 10 = 4 students. 16 students = 4 lots of 10% = 40%.
Q: Sam gives ยฃ30 to his sister, spends half of the rest on presents, and has ยฃ20 left. How much did he start with?
Work backwards: ยฃ20 left is half of remaining โ remaining before presents = ยฃ40. Before ยฃ30 sister gift = ยฃ40 + ยฃ30 = ยฃ70.
Q: A jacket is ยฃ80. It is in a sale with 25% off. What is the sale price?
Whole 100% = ยฃ80. Discount 25% = ยฃ20. Sale price 75% = ยฃ80 โ ยฃ20 = ยฃ60.
๐ Ready to Test Your Knowledge?
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