#3
Constructing fractions
Number · Grade 1–3
Strand: Number
Substrand: Fractions and mixed numbers
Sparx code: U163
Sparx levels: 1, 2
Key steps (method)
- Simplify fractions where possible before doing any calculations.
- To add/subtract: use a common denominator, then combine numerators.
- To multiply: multiply numerators and denominators (cancel common factors first).
- To divide: multiply by the reciprocal.
- Convert improper fractions to mixed numbers only at the end if asked.
Common mistakes
- Adding denominators when adding fractions (you don’t).
- Forgetting to use the reciprocal when dividing.
- Not simplifying/cancelling, leading to messy arithmetic mistakes.
Quick notes
- If you get stuck, try a simpler version of the problem first or plug in easy numbers to test your method.
- For multi-step questions, label each step and keep intermediate results.
- For exam questions, always aim to make your work “mark-scheme readable”.
Self-assessment
- Can I define it? Write a one-sentence definition of Constructing fractions (or the key term in the question).
- Can I do it? Do 3 questions: one easy, one standard, one harder. Don’t look at notes until you’ve tried.
- Can I explain it? In 2–3 sentences, explain why the method works (or what would go wrong with a common mistake).
- Can I check it? State one quick check (estimate, units, sign, reasonableness).
Support videos
- YouTube (Edexcel GCSE Maths): https://www.youtube.com/results?search_query=edexcel%20gcse%20maths%20Constructing%20fractions
- YouTube (Corbettmaths): https://www.youtube.com/results?search_query=corbettmaths%20Constructing%20fractions
- YouTube (Maths Genie): https://www.youtube.com/results?search_query=maths%20genie%20Constructing%20fractions
Revision links
- Sparx topic code: U163 (paste into Sparx search)
- 1st Class Maths video: https://www.youtube.com/watch?v=rL18ZMgCeKU
- 1st Class Maths exam questions: https://www.1stclassmaths.com/_files/ugd/9f3fb0_e86cf01165c84b9b98a3fbf79b009290.pdf
- Solutions: https://www.1stclassmaths.com/_files/ugd/9f3fb0_b5b8ba631ce94e809634da53d54618cd.pdf
- Edexcel past papers (pack): (to be added)
- Maths Genie (topic questions): https://www.mathsgenie.co.uk/gcse.html
- Physics & Maths Tutor (Edexcel GCSE Maths): https://www.physicsandmathstutor.com/maths-revision/gcse-edexcel/