Non-Calculator Percentages

Non-Calculator Percentages in NSW Year 8 maths (NESA outcome MA4‑FRC‑C‑01) builds percentages in your head from a few easy pieces: 10% is a tenth, 1% is a hundredth, and 50%, 25% and \(12\frac{1}{2}\%\) come from halving.

You will combine parts, as in \(65\% = 50\% + 10\% + 5\%\), use benchmark fractions like \(33\frac{1}{3}\% = \frac{1}{3}\), take a discount off a pair of runners, add growth to a school’s enrolment and find a whole from a part when 15% of a survey is 27 students. You will also estimate with friendly numbers and \(\approx\), the way you would check a sale sign before reaching the register. It is part of Year 8 Fractions and Percentages.