YEAR 8 GUIDE · PHASE 3

Year 8 maths · explained

A parent and teacher guide to Year 8 of the refreshed NZ maths curriculum — what’s taught, how to spot readiness, and how to help at home.

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PHASE 3 · YEARS 7–8YEAR 8ALL YEARS

Where Year 8 fits

Year 8 is the final year of Phase 3 — and of primary maths. Everything sharpens and points at high school: prime factorisation, percentage change, ratio, real budgets, and algebra with brackets. Remember the golden rule of the refreshed curriculum: it's progression-based — children move on when they're ready, not on a birthday. Treat year levels as a guide only.

What children learn in Year 8 Number

Children extend powers of 10 in both directions (negative exponents give decimals), meet cube roots, and write numbers as prime factorisations with exponents (36 = 2² × 3²). They evaluate integer expressions like 3 + (−7), multiply fractions and multiply decimals (2.3 × 45), and master percentage increase and decrease — including finding the original from a changed amount. Ratio becomes formal: dividing a quantity part-to-part or part-to-whole. Money maths becomes life maths: comparing savings plans, phone plans and budgets. In algebra they solve equations with rational answers, handle inequalities, simplify expressions and factorise (5x − 35 = 5(x − 7)).

negative exponentscube rootsprime factorisationinteger expressionsmultiply fractionsmultiply decimals% increase & decreaseratiobudgets & plansinequalitiesfactorising

✅ Signs your child is ready for high school

  • Writes a number like 72 as a prime factorisation with exponents
  • Handles percentage increase and decrease — including working backwards
  • Splits a quantity in a given ratio (share $60 in the ratio 2 : 3)
  • Solves and rearranges simple equations, and simplifies expressions with brackets

Five ways to help at home 🏡

1. Hand over a real budget

A week of school lunches, a birthday party, their phone plan. Comparing plans and budgets is literally the Year 8 money curriculum.

2. Chase percentage change in the news

'Butter up 12%', 'membership down 8%' — what was it before? Working backwards from a change is the skill high school assumes.

3. Cook in ratios

'Juice concentrate 1 : 4 — how much of each for 1.5 litres?' Ratio moves from abstract to obvious in a kitchen.

4. Factor-tree big numbers

Pick a number like 360 and race to its prime factorisation. Exponent notation as a party trick.

5. Let algebra describe real patterns

Taxi fares, phone plans: '$5 plus $2 per km — write the rule.' Linear rules from real life are exactly where Year 8 algebra lands.

Practise Year 8 with a mystery

Every Year 8 mystery on Kiwi123 practises one focus skill from this year, inside a whodunit — so the maths practice feels like detective work, not drill. Browse the Year 8 mysteries → Or see everything in Phase 3 (Years 7–8).

Ready to crack a case? 🔎

Every Year 8 mystery practises one skill from this year inside a whodunit maths activity. The first ones are free — no account needed.

Open the Year 8 mysteries →