Mathematics
70 articlesAlgebra
32- Divisibility RulesNewβ
Divisibility rules are quick tests that tell you whether one number divides evenly into another without having to do the full division.
- Long DivisionNewβ
Long division is a step-by-step written method for dividing large numbers, repeating the cycle of divide, multiply, subtract, and bring down.
- Long MultiplicationNewβ
Long multiplication breaks a multi-digit multiplication into smaller steps using partial products, then adds them together.
- Order of Operations (BODMAS)Newβ
BODMAS gives the correct sequence for evaluating expressions with multiple operations: Brackets, Orders, Division, Multiplication, Addition, Subtraction.
- Written Column AdditionNewβ
Column addition lines up numbers by place value and adds from right to left, carrying any overflow into the next column.
- Written Column SubtractionNewβ
Column subtraction lines up numbers by place value and subtracts from right to left, borrowing from the next column when needed.
- Inequalities β Solving and Representing on a Number Lineβ β
An inequality compares two expressions using <, >, β€ or β₯. Solving an inequality is like solving an equation, except that multiplying or dividing by a negative number reverses the inequality sign.
- Linear Equationsβ
A linear equation is an algebraic equation where each term is either a constant or a single variable raised to the first power.
- Substitution β Evaluating Algebraic Expressionsβ
Substitution means replacing a letter (variable) in an expression with a given number and then calculating the result. It is used to evaluate formulae and check solutions to equations.
- Systems of Equationsβ β
A system of equations is a set of two or more equations with the same variables, solved simultaneously.
- Two-Step Equationsβ β
A two-step equation needs exactly two operations to isolate the variable. Undo addition or subtraction first, then undo multiplication or division.
- Writing Equations from Word Problemsβ β
How to translate word problems into algebraic equations and solve them step by step.
- Adding and Subtracting Fractionsβ β
To add or subtract fractions, first rewrite them with a common denominator (LCD), then add or subtract the numerators.
- Dividing Fractionsβ β
To divide by a fraction, multiply by its reciprocal β flip the second fraction and multiply.
- Equivalent Fractionsβ β
Two fractions are equivalent when they represent the same value. Multiply or divide both the numerator and denominator by the same non-zero number.
- Multiplying Fractionsβ β
Multiply fractions by multiplying numerator by numerator and denominator by denominator. No common denominator needed.
- Subtracting Fractionsβ
How to subtract fractions with the same and different denominators, including mixed numbers.
- Algebra FundamentalsNewβ
Foundation of mathematics covering numbers, expressions, equations, and problem-solving skills that build all higher mathematics.
- Comparing and Ordering Natural NumbersNewβ
Use the symbols <, >, and = to compare natural numbers, and arrange them in ascending or descending order using place value and the number line.
- Place Value in Natural NumbersNewβ
Every digit in a number has a place value β its position tells you how much it is worth. Learn to read, write, and expand large numbers up to millions.
- Rounding Natural NumbersNewβ
Rounding replaces a number with a nearby "round" number that is easier to work with. Learn to round to the nearest 10, 100, 1 000, and 10 000.
- Percent Changeβ β β
Percent change measures how much a value has increased or decreased relative to its original value, expressed as a percentage.
- Percent of a Numberβ β
A percentage is a fraction out of 100. To find a percentage of a number, multiply the number by the percentage divided by 100.
- Simple Interest and Percentages in Financeβ β β
Simple interest is calculated on the original principal only. The formula I = PRT links the interest, principal, rate, and time. Compound interest is briefly introduced as interest on interest.
- VAT, Discounts, and Sale Pricesβ β
VAT (Value Added Tax) is a percentage added to a price. Discounts are percentages subtracted from a price. Knowing how to calculate both is an essential everyday maths skill.
- Completing the Squareβ β β β
Completing the square rewrites a quadratic expression axΒ² + bx + c in the form a(x + p)Β² + q. This technique is used to solve quadratics, find the vertex of a parabola, and derive the quadratic formula.
- The Discriminantβ β
The discriminant of a quadratic equation determines how many and what type of roots the equation has.
- The Quadratic Formulaβ β
The quadratic formula solves any quadratic equation axΒ² + bx + c = 0 by finding the roots in terms of a, b, and c.
- Direct Proportionβ β
Two quantities are in direct proportion when they increase and decrease at the same rate. If one doubles, the other doubles too. The relationship is written y = kx, where k is the constant of proportionality.
- Inverse Proportionβ β β
Two quantities are in inverse proportion when one increases as the other decreases by the same factor. The product of the two quantities is always constant, and the formula is y = k/x.
- Dividing a Quantity in a Given Ratioβ β
To divide a quantity in a given ratio, find the value of one part by dividing the total by the sum of the ratio parts, then multiply each ratio number by one part.
- Ratios and Proportionsβ β
A ratio compares two quantities. A proportion states that two ratios are equal. Proportions are solved using cross-multiplication.
Geometry
32- Types of Anglesβ
Angles are classified by their measure in degrees β acute, right, obtuse, straight, and reflex. Understanding angle types is the foundation of geometry.
- Angles on a Line and at a Pointβ β
Angles on a straight line sum to 180Β°. Angles around a full point sum to 360Β°. Vertically opposite angles are always equal.
- Angles in Parallel Linesβ β
When a transversal crosses two parallel lines, it creates pairs of equal angles (corresponding and alternate angles) and supplementary angle pairs (co-interior angles that add up to 180Β°).
- Interior Angles of Polygonsβ β
The sum of the interior angles of any polygon depends only on the number of sides. For an n-sided polygon the sum is (n β 2) Γ 180Β°. Regular polygons have all angles equal, so each interior angle = sum Γ· n.
- Angles in a Triangleβ
The angle sum property of triangles and exterior angle theorem with examples.
- Area of Compound Shapesβ β
A compound shape is made up of two or more simple shapes joined together. To find the total area, split the compound shape into rectangles, triangles, or other familiar shapes, calculate each area separately, and add them up.
- Units of Measurement and ConversionNewβ
Explore the units used to measure length, mass, time, and volume, and practise converting between them using the correct conversion factors.
- Area and Perimeter of a Parallelogramβ
Formulas for the area and perimeter of a parallelogram with worked examples.
- Area and Perimeter of a Rectangleβ
Formulas for the area and perimeter of a rectangle, including worked examples.
- Area & Perimeter β Quick Reference Cardsβ
Formula cards for the area and perimeter of all common 2D shapes.
- Area and Perimeter of a Squareβ
Formulas for the area, perimeter, and diagonal of a square, with worked examples.
- Area and Perimeter of a Trapezoidβ β
Formulas for the area and perimeter of a trapezoid with worked examples.
- Area and Perimeter of a Triangleβ β
How to calculate the area and perimeter of triangles using base-height and Heron's formula.
- Arcs and Sectors of a Circleβ β β
An arc is part of the circumference; a sector is a pie-slice of a circle. Both are calculated as a fraction of the full circle, where the fraction = angle Γ· 360.
- Area and Circumference of a Circleβ
Formulas for the area and circumference of a circle, and how to apply them.
- Circumference of a Circleβ β
The circumference is the distance around the outside of a circle. It equals Ο multiplied by the diameter, or 2Ο multiplied by the radius.
- Measuring and Drawing AnglesNewβ
An angle is formed by two rays sharing a vertex. Learn to identify angle types, use a protractor to measure angles, and draw angles of any given size.
- Constructing TrianglesNewβ
A triangle is a three-sided polygon. Learn the triangle inequality, how to construct triangles from given measurements using compass and ruler, and the main types of triangles.
- Drawing and Bisecting Line SegmentsNewβ
A line segment is a straight path between two fixed points. Learn how to draw segments of a given length, measure them, and find the midpoint using a compass.
- The Coordinate Planeβ β
The coordinate plane uses two perpendicular number lines (axes) to locate any point using an ordered pair (x, y). It is divided into four quadrants.
- Gradient of a Lineβ β
The gradient (slope) of a line measures how steep it is β how much the line rises or falls for every unit it moves to the right. Gradient = change in y Γ· change in x (rise Γ· run).
- Midpoint and Distance Between Two Pointsβ β
The midpoint of a line segment is the point exactly halfway between its endpoints. The distance formula uses Pythagoras' theorem to find the straight-line distance between any two points on a coordinate grid.
- Straight-Line Graphs β y = mx + cβ β
Every straight-line graph can be written as y = mx + c, where m is the gradient (steepness) and c is the y-intercept (where the line crosses the y-axis). Knowing these two values is enough to draw or describe any straight line.
- Geometry FundamentalsNewβ
Study of shapes, space, and measurement covering angles, areas, volumes, coordinates, and spatial reasoning.
- Volume and Surface Area of a Coneβ β
Formulas for the volume and surface area of a cone with worked examples.
- Surface Area and Volume of a Cubeβ
How to calculate the surface area and volume of a cube and rectangular box.
- Volume and Surface Area of a Cuboidβ
Formulas for the volume and surface area of a cuboid (rectangular box) with worked examples.
- Surface Area and Volume of a Cylinderβ β
Formulas for computing the surface area and volume of a cylinder.
- Volume & Surface Area β Quick Reference Cardsβ
Formula cards for the volume and surface area of all common 3D solids.
- Volume and Surface Area of a Sphereβ β
Formulas for the volume and surface area of a sphere with worked examples.
- Line SymmetryNewβ
A shape has line symmetry when it can be folded along a line so that both halves match exactly. Learn to identify axes of symmetry in common shapes, regular polygons, and everyday letters.
- Rotational SymmetryNewβ
A shape has rotational symmetry when it looks the same after being rotated less than a full turn about a fixed centre point. Explore the order of rotational symmetry and point (central) symmetry.
Trigonometry
6- Trigonometry FundamentalsNewβ
Study of triangle relationships and periodic functions using angles, trigonometric ratios, and their applications.
- The Pythagorean Theoremβ
The Pythagorean theorem relates the three sides of a right triangle: aΒ² + bΒ² = cΒ².
- Trigonometry in Real Life β Angles of Elevation and Depressionβ β β
Angles of elevation (looking up) and depression (looking down) are measured from the horizontal. Combined with trigonometry, they allow us to find heights, distances, and positions in the real world.
- Sine, Cosine and Tangentβ β
The three primary trigonometric ratios: sine, cosine, and tangent in a right triangle.
- SOHCAHTOA β Finding Missing Sidesβ β
SOHCAHTOA is a mnemonic for the three trigonometric ratios in a right-angled triangle. It is used to find missing side lengths when an angle and one side are known.
- Finding Angles Using Trigonometryβ β β
When you know two sides of a right-angled triangle, you can use the inverse trigonometric functions (arcsin, arccos, arctan) to find a missing angle.