Prime Factors

Every whole number greater than 1 can be written as a product of primes in exactly one way. In NSW Year 8 maths you find that product with a factor tree or repeated division and write it in index form, such as \(300 = 2^2 \times 3 \times 5^2\) (NESA outcome MA4‑IND‑C‑01).

You will use prime factors to find the highest common factor (HCF) and lowest common multiple (LCM), divide large numbers, and find roots such as \(\sqrt{8100}\) and \(\sqrt[3]{512}\) without a calculator. You will also find the smallest number to multiply or divide by to make a square or a cube. Cutting ribbons into equal pieces and tiling the smallest square from rectangles are HCF and LCM problems. It is part of Year 8 Working with Numbers.