A percentage is a number expressed as a fraction of 100. "Per cent" literally means per hundred — so 35% means 35 out of every 100. Percentages are everywhere: shop discounts, test scores, weather forecasts and nutrition labels all use them!
…%
0%25%50%75%100%
🍬 The Golden Rules:
Per cent = out of 100: 47% = 47100. To convert a fraction to %, make the denominator 100 (or divide top ÷ bottom × 100).
Decimal ↔ Percentage: Multiply by 100 to get % (move the decimal 2 places right). Divide by 100 to get decimal (move 2 places left).
To find 10%: Divide the amount by 10. Build other percentages from this — 5% is half of 10%, 20% is double 10%, 1% is 10% ÷ 10.
To find 1%: Divide the amount by 100. Then multiply by any percentage you need.
Percentage increase / decrease: Find the % of the amount, then add (increase) or subtract (decrease) from the original.
📊 Key Conversions to Know:
Percentage
Fraction
Decimal
10%
110
0.1
20%
15
0.2
25%
14
0.25
50%
12
0.5
75%
34
0.75
1%
1100
0.01
100%
1 whole
1.0
📝 Worked Examples
Study each example carefully before moving to the drag and practice sections!
Example 1: Converting a Fraction to a Percentage
Question: Write 34 as a percentage.
Step 1: Divide the numerator by the denominator: 3 ÷ 4 = 0.75
Step 2: Multiply by 100: 0.75 × 100 = 75%
Shortcut:34 → multiply top and bottom by 25 → 75100 = 75%
Answer: 75%
Example 2: Converting a Decimal to a Percentage
Question: Write 0.35 as a percentage.
Step 1: Multiply by 100 (move the decimal point 2 places to the right).
0.35 × 100 = 35%
Remember: To convert % → decimal, divide by 100 (move decimal 2 places LEFT). So 35% ÷ 100 = 0.35 ✔
Answer: 35%
Example 3: Finding 10% and Building Other Percentages
Question: Find 35% of 80.
Step 1: Find 10% → 80 ÷ 10 = 8
Step 2: Find 30% → 8 × 3 = 24
Step 3: Find 5% → 8 ÷ 2 = 4
Step 4: Add them → 30% + 5% = 35% → 24 + 4 = 28
Answer: 35% of 80 = 28
Example 4: Percentage Decrease (Sale Price)
Question: A pair of trainers costs £60. They are reduced by 20% in a sale. What is the sale price?
Step 1: Find 10% of £60 → £60 ÷ 10 = £6
Step 2: Find 20% → £6 × 2 = £12
Step 3: Subtract from original → £60 − £12 = £48
Answer: Sale price = £48
🔬 Percentage Bar Calculator
Type any amount and percentage below. Watch the bar fill up and see the result — plus the fraction and decimal equivalents!
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0%25%50%75%100%
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📋 Quick Conversion Reference
%
Fraction
Decimal
How to find it
1%
1/100
0.01
÷ 100
5%
1/20
0.05
÷ 10 then ÷ 2
10%
1/10
0.1
÷ 10
20%
1/5
0.2
÷ 10 then × 2
25%
1/4
0.25
÷ 4
50%
1/2
0.5
÷ 2
75%
3/4
0.75
÷ 4 × 3
100%
1 whole
1.0
the whole amount
🧩 Drag 1: Fractions to Percentages
Convert the fraction to a percentage. Drag the correct answer into the box!
20
50
25
12=%
🧩 Drag 2: Decimals to Percentages
Convert the decimal to a percentage. Multiply by 100 (move the decimal point 2 places right)!
3.5
35
350
0.35 =%
🧩 Drag 3: Finding 10%
To find 10%, divide by 10. Drag the correct answer!
6
16
60
10% of 60 =
🧩 Drag 4: Finding 25%
To find 25%, divide by 4 (or halve, then halve again). Drag the correct answer!
25
50
100
25% of 200 =
🧩 Drag 5: Finding 50%
To find 50%, divide by 2. Drag the correct answer!
21
42
84
50% of 84 =
🧩 Drag 6: Building Any Percentage
To find 15% of 80: first find 10% (= 8), then find 5% (half of 10% = 4), then add them. Drag the final answer!
8
12
16
15% of 80 =
(Hint: 10% of 80 = 8 | 5% of 80 = 4 | 8 + 4 = ?)
📝 Practice Questions
Grab your paper and pencil — show all your working!
Write 34 as a percentage.
Write 0.6 as a percentage.
Write 40% as a fraction in its simplest form.
Write 85% as a decimal.
Find 10% of 70.
Find 50% of 124.
Find 25% of 80.
Find 1% of 600.
Find 5% of 40.
Find 20% of 85.
Find 15% of 60. (Hint: find 10% then 5%)
Find 75% of 200.
Write 720 as a percentage.
Find 30% of 90.
A jacket costs £50. It is reduced by 20%. What is the sale price?
Write 35 as a percentage.
Find 35% of 200.
65% of pupils in a class of 20 walk to school. How many pupils walk?
Write 0.08 as a percentage.
Find 45% of 80.
75%
60%
25
0.85
7
62
20
6
2
17
9 (10% = 6, 5% = 3, 6 + 3 = 9)
150
35%
27
£40 (20% of £50 = £10 | £50 − £10 = £40)
60%
70
13 pupils (65% of 20 = 10% × 6.5 = 13)
8%
36 (10% = 8, 40% = 32, 5% = 4, 45% = 36)
🔥 Challenge: Word Problems
Show all your workings on paper. These are exam-style questions!
A shop sells trainers for £120. In a sale, the price is reduced by 15%. What is the sale price?
In a class of 30 pupils, 40% are girls. How many girls are in the class?
A mobile phone originally costs £80. VAT of 20% is added. What is the total price including VAT?
Maria scored 36 out of 40 on a test. What percentage did she score?
A recipe requires 250 g of flour. Jamie uses 60% of the flour. How many grams does he use?
A car is worth £8,000. Its value drops by 25% in the first year. What is the car worth after one year?
35% of children in a class of 20 have a pet dog. How many children have a pet dog?
A shop has 150 items in stock. 30% of the items are sold in a sale. How many items remain?
Harry scores 45 out of 60 in a maths test. What percentage does he score?
A tree is 4 m tall. It grows by 15% during the year. How tall is the tree now?