Find percentages of a quantity - Find 25% & 50%
Theory
\(50\%\) is one half and \(25\%\) is one quarter. So to find \(50\%\) of an amount, divide it by \(2\); to find \(25\%\), divide it by \(4\); and \(75\%\) is three of those quarters. This Year 6 maths page shows how to find these percentages of numbers, money and measurements, and how to find the whole when you know a part.
\(50\% = \dfrac{50}{100} = \dfrac{1}{2}\). To find \(50\%\), divide by 2 (halve).
\(25\% = \dfrac{25}{100} = \dfrac{1}{4}\). To find \(25\%\), divide by 4, or halve and halve again.
\(75\% = \dfrac{3}{4}\). To find \(75\%\), find \(25\%\) and multiply by \(3\) (or take \(25\%\) away from the whole).
The answer can be a decimal: \(50\%\) of \(9\) is \(4.5\).
\(25\% + 25\% + 50\% = 100\%\), the whole amount.
Percentages that are halves and quarters:
How to find 50% or 25%
- 50%: divide the amount by \(2\).
- 25%: divide the amount by \(4\) (or halve twice).
How to find 75%
- Find \(25\%\).
- Multiply by \(3\).
How to find the whole
- From 50%: multiply by \(2\).
- From 25%: multiply by \(4\).
| \(96 \div 2\) | \(=\) | \(48\) |
| \(96 \div 4\) | \(=\) | \(24\) |
\(50\%\) is \(48\) and \(25\%\) is \(24\).
| \(96 \div 4\) | \(=\) | \(24\) |
| \(3 \times 24\) | \(=\) | \(72\) |
\(72\).
| \(9 \div 2\) | \(=\) | \(4.5\) |
\(4.5\).
(i) \(25\%\) of \(140\) kg
(ii) \(25\%\) of \(\$30\)
| \(140 \div 4\) | \(=\) | \(35\) |
| \(30 \div 4\) | \(=\) | \(7.5\) |
(i) \(35\) kg
(ii) \(\$7.50\)
(i) How many walk?
(ii) How many come by car?
(iii) How many do neither?
| \(28 \div 4\) | \(=\) | \(7\) |
| \(28 \div 2\) | \(=\) | \(14\) |
| \(28 - 7 - 14\) | \(=\) | \(7\) |
(i) \(7\)
(ii) \(14\)
(iii) \(7\) (the last \(25\%\))
(ii) \(25\%\) of a number is \(11\). What is the number?
| \(23 \times 2\) | \(=\) | \(46\) |
| \(11 \times 4\) | \(=\) | \(44\) |
(i) \(46\)
(ii) \(44\)
| \(360 \div 4\) | \(=\) | \(90\) |
| \(3 \times 90\) | \(=\) | \(270\) |
\(270\) L, as in the second diagram.
| \(64 \div 4\) | \(=\) | \(16\) |
\(25\%\) is one quarter, so divide by \(4\). The answer is \(16\).
Common pitfalls
Frequently asked questions
How do you find 50% of an amount?
Divide it by \(2\). \(50\%\) of \(96\) is \(48\).
How do you find 25% of an amount?
Divide it by \(4\), or halve it twice.
How do you find 75%?
Find \(25\%\) and multiply by \(3\).
Why is 25% the same as one quarter?
\(25\) out of \(100\) is \(\dfrac{25}{100} = \dfrac{1}{4}\).
If 25% is 11, what is the whole?
\(4 \times 11 = 44\).