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Grade 9 · Maths
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1. Real Numbers and Measurement Accuracy
  1. Use rational and irrational values in calculationsFree lesson
  2. Extend exponent laws to variables with stated restrictionsIn preparation
  3. Round to decimal places or significant figuresIn preparation
  4. Calculate and interpret absolute and percentage measurement errorIn preparation
2. Algebraic Structure and Formulas
  1. Multiply two simple binomials with an area modelIn preparation
  2. Factorise common factors and simple monic quadraticsIn preparation
  3. Rearrange linear formulas with stated restrictionsIn preparation
  4. Verify equivalent expressions using expansion rather than a single inputIn preparation
3. Functions and Coordinate Connections
  1. Compare linear and simple quadratic patterns in tables and graphsIn preparation
  2. Interpret zeros and turning behaviour in a contextual graphIn preparation
  3. Find midpoint and gradient between two pointsIn preparation
  4. Explore how a parameter changes a graphIn preparation
4. Equations, Inequalities and Feasibility
  1. Model a constraint using an equation or inequalityIn preparation
  2. Solve linear systems and interpret feasible solutionsIn preparation
  3. Solve simple factorisable quadratics using the zero-product principleIn preparation
  4. Reject solutions that violate the original contextIn preparation
5. Similarity and Right-Triangle Trigonometry
  1. Use similarity to justify constant side ratios for a fixed angleIn preparation
  2. Identify opposite, adjacent and hypotenuse relative to an angleIn preparation
  3. Use sine, cosine and tangent to find a sideIn preparation
  4. Find an angle using an inverse trigonometric functionIn preparation
  5. Check units, calculator mode and plausibilityIn preparation
6. Scale, Surface and Spatial Models
  1. Relate length scale to area and volume scaleIn preparation
  2. Solve composite surface-area and volume problemsIn preparation
  3. Choose an appropriate geometric approximationIn preparation
  4. Test a spatial result against measurements and assumptionsIn preparation
7. Data Quality and Compound Probability
  1. Compare distributions and discuss outliers and samplingIn preparation
  2. Critique a misleading display or unsupported inferenceIn preparation
  3. List compound outcomes with and without replacementIn preparation
  4. Calculate dependent and independent event probabilitiesIn preparation
  5. Check a probability model with simulationIn preparation
8. Community-Space Modelling Project
  1. Define a design question and measurable constraintsIn preparation
  2. Build a geometric and cost modelIn preparation
  3. Test sensitivity to one changed assumptionIn preparation
  4. Evaluate survey evidence responsiblyIn preparation
  5. Present and defend a feasible proposalIn preparation

Exact Values, Sensible Approximations

PRACTISE · ONE IDEA AT A TIME

Your turn to think

Try one question. A hint can help!

Rational numbers · Question 1 of 6

√25 is…

Read together with an adult.
Choose an answer

Use rational and irrational values in calculations.

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For parents

What you have practised

0 answered independently · 0 completed with help. These are practice results, not a formal assessment.

  • Rational numbersNot tried yet
  • Irrational numbersNot tried yet
  • Exact calculationNot tried yet
  • Final roundingNot tried yet
  • Exact calculationNot tried yet
  • Geometry transferNot tried yet

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About this lesson

Use rational and irrational values in calculations.

Suggested ages: 14–15. Choose from your child’s existing skills, not age alone.

This lesson includes a video, six exercises and three game missions. Instructions and feedback can be heard aloud.

Before this unit

  • Grade 8: Exponents, Roots and Scientific Notation
  • Grade 8: Pythagoras and Distance

A structured skills programme, not a school qualification.