Ratio & Proportion
Write and simplify ratios, share a quantity in a given ratio, and solve simple direct proportion problems.
Overview
A ratio compares two or more quantities, and proportion describes how quantities change together. In Year 7 students write and simplify ratios, share an amount in a given ratio, and solve simple direct proportion problems such as recipes and best-buy comparisons. Ratio links closely to fractions and is used heavily in everyday life.
What You Will Learn
- Write a ratio to compare two or more quantities
- Simplify a ratio to its simplest whole-number form
- Divide a quantity into a given ratio
- Solve simple direct proportion problems, such as scaling a recipe
- Use the unitary method to find the value of one part
Key Vocabulary
Common Mistakes to Avoid
- Treating a ratio like a fraction of the whole (in 2:3 the first part is 2/5 of the total, not 2/3)
- Forgetting to add the parts together before dividing the total
- Not simplifying a ratio fully, e.g. leaving 4:6 instead of 2:3
- Mixing up the order of the quantities in the ratio
What Comes Next
Year 8 develops this into ratio with three parts, map scales and inverse proportion, and Year 9 reaches proportional reasoning with algebra. Ratio and proportion remain a major IGCSE Number theme.
Frequently Asked Questions
Is a ratio the same as a fraction?
They are related but not the same. A ratio compares parts to each other (2:3), while a fraction compares a part to the whole (2/5 of the total).
What is the unitary method?
It means finding the value of one unit or one part first, then multiplying up. If 3 pens cost RM6, one pen costs RM2, so 5 pens cost RM10.
Study This Topic
Topic Details
- Stage
- Year 7
- Strand
- Number
- Framework ref
- 7Nf
- Difficulty
- Medium
Build strong foundations in Ratio & Proportion
A free trial class with Teacher Rig helps your Year 7 child master Ratio & Proportion now — so IGCSE Maths feels familiar, not frightening, later.
Heading toward IGCSE? See how Ratio & Proportion develops in IGCSE Number (Cambridge 0580) →