The hard topics, made simple.
14 free guides to the GCSE and IGCSE maths topics students find hardest. Each one starts with a picture that makes the idea click, then walks through worked examples, the traps examiners set, and 297 exam-style questions in all, with every answer and its working. Read them here or download the PDF to print.
Reverse percentages and compound interest
The price-tag machine: 4 worked examples and 22 exam-style questions with answers.
Indices (powers)
The multiplying machine: 4 worked examples and 23 exam-style questions with answers.
Rearranging formulae
Unwrapping a present: 4 worked examples and 20 exam-style questions with answers.
Sequences and the nth term
A staircase: 4 worked examples and 21 exam-style questions with answers.
Factorising quadratics
A rectangle of tiles: 4 worked examples and 23 exam-style questions with answers.
Simultaneous equations
Two café receipts: 4 worked examples and 23 exam-style questions with answers.
Inequalities
A tipped see-saw: 4 worked examples and 20 exam-style questions with answers.
Direct and inverse proportion
A pizza party: 4 worked examples and 21 exam-style questions with answers.
Upper and lower bounds
The rounding bucket: 4 worked examples and 21 exam-style questions with answers.
Completing the square and the quadratic formula
The square with a corner missing: 4 worked examples and 20 exam-style questions with answers.
Surds
The square-root bouncer: 4 worked examples and 23 exam-style questions with answers.
Algebraic fractions
Pizza slices: 4 worked examples and 22 exam-style questions with answers.
Recurring decimals to fractions
A song stuck on repeat: 4 worked examples and 19 exam-style questions with answers.
Functions: composite and inverse
Machines on a conveyor belt: 4 worked examples and 19 exam-style questions with answers.
Prefer to watch? Our one-minute video lessons explain one idea at a time.