Fractions of a Quantity

Fractions of a Quantity in NSW Year 8 maths (NESA outcome MA4‑FRC‑C‑01) finds a fraction of an amount by dividing by the denominator and multiplying by the numerator, so \(\frac{5}{6}\) of 216 km is \(216 \div 6 \times 5 = 180\) km.

You will change units first (\(\frac{5}{12}\) of an hour is 25 minutes), use mixed numerals such as \(1\frac{2}{3}\) of 45 L, increase an amount by a fraction, take a fraction of what is left and work backwards from a part to the whole. You will also judge whether the answer should be more or less than the quantity before working it out. Bus fares, planks of wood and bottles of juice are typical contexts. It is part of Year 8 Fractions and Percentages.