Percentage of a Quantity (harder)

This subtopic tackles harder percentage questions, such as 14% of 550 swimmers or a console with 25% off. In NSW Year 7 maths (NESA outcome MA4‑FRC‑C‑01) it adds percentage increase and decrease, discounts, GST and profit.

You will build awkward percentages from easy parts, use a multiplier to increase or decrease in one step, and work backwards with the unitary method: if 480 girls are 30% of a school, there are 1600 students. Multi-step questions, such as saving 15% of a wage and then paying rent, check that each percentage is taken of the right amount. This subtopic is part of Year 7 Percentages.