Maths topics explained — with practice questions
Pick a topic for the formula, worked examples, common mistakes and practice questions with answers. Each topic links to the chapters for every class.
Area of a rectangleHow to find the area of a rectanglePerimeter of a rectangleLearn the perimeter of a rectangleArea of a triangleFind the area of a triangle with ½ × base × height or Heron's formula.Area and circumference of a circleFormulas for the area and circumference of a circle, with worked exampHCF and LCMHow to find the HCF and LCM of numbers using prime factorisation, withPercentageHow to calculate percentages, percentage increase and decrease, with wProfit and lossProfit and loss explainedSimple interestThe simple interest formula SI = PRT/100 with worked examples for inteFractionsHow to add, subtract and simplify fractions, including unlike denominaPythagoras theoremThe Pythagoras theorem a² + b² = c²Prime numbers and factorisationWhat prime and composite numbers are, how to test a number, and how toRatio and proportionLearn ratio and proportionLinear equations in one variableHow to solve linear equations in one variable, including equations witAlgebraic identitiesThe standard algebraic identities (a+b)², (a−b)², a²−b² and (x+a)(x+b)Mean, median and modeHow to find the mean, median and mode of a data set, when to use each,Squares and square rootsLearn squares and square rootsQuadratic equationsSolve quadratic equations by factorisation and by the quadratic formulTrigonometric ratiosLearn sin, cos and tan, the values for 0°, 30°, 45°, 60° and 90°, and ProbabilityLearn probabilityVolume and surface area of solidsFormulas for the volume and surface area of a cuboid, cube, cylinder aOperations on integersRules for adding, subtracting, multiplying and dividing positive and nLaws of exponentsThe laws of exponents for multiplying, dividing and raising powers, in