This exam tips covers Common Mistakes to Avoid within Proportion for GCSE Mathematics. Revise Proportion in Number for GCSE Mathematics with 12 exam-style questions and 22 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 14 of 15 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 14 of 15
Practice
12 questions
Recall
22 flashcards
Common Mistakes to Avoid
❌ Wrong: Confusing direct and inverse relationships
✅ Right: Check: if one increases, does other increase (direct) or decrease (inverse)?
Draw a mental graph - straight line (direct) or curve (inverse)?
❌ Wrong: Forgetting to find k first
✅ Right: Always find the constant before solving
Use the given values to find k, then substitute back
❌ Wrong: Using y = kx for inverse proportion
✅ Right: Inverse is y = k/x or xy = k
Check which formula fits the relationship type
❌ Wrong: Not checking answers make sense
✅ Right: Verify the direction of change is correct
If x doubles, should y double (direct) or halve (inverse)?