Writing & Simplifying Ratios — GCSE Foundation · Ratio & proportion · Year 10.

Write ratios using colon notation, simplify every part by the HCF, and nail the habit that trips pupils first — the order in the ratio must match the order in the question.

Exam board alignment: Covers Foundation ratio skills required by OCR J560, AQA 8300 and Edexcel 1MA1. Written at an OCR Foundation school; sequence follows a ratio unit opener.

What’s included

• 4-page student worksheet (print-ready PDF)
• 2-page teacher answer key with full worked solutions and section-by-section notes
• Do Now — quick arithmetic warm-up (division and HCF prep)
• Retrieval — colon notation, HCF, and simplifying fractions from prior learning
• The Big Idea — order matters · divide every part by the HCF · equivalent ratios
• I Do / We Do — simplify 12 : 18, write ratios from context, boys : girls
• Spot the Mistake — Alex writes apples : oranges as 5 : 8 when there are 8 apples and 5 oranges
• You Do — Section A (simplify & equivalence) · Section B (four scenario cards)
• Going Deeper — three-part ratios · decimals in ratios
• Exit ticket + self-assessment checkboxes

Lessons with teacher commentary, not just answers — diagnostic notes on the misconception, marking guidance.