1 мин чтения
Fractions: simplifying, adding, multiplying and dividing
What a fraction means, how to simplify one, and the four operations — with a common denominator only when you need it.
Простые объяснения тем, о которых ученики спрашивают чаще всего. Каждый урок начинается с идеи, разбирает пример шаг за шагом и проверяет ответ математическим движком Sumzo — а затем ведёт к калькулятору и тренировочным заданиям.
1 мин чтения
What a fraction means, how to simplify one, and the four operations — with a common denominator only when you need it.
1 мин чтения
Break numbers into primes, then use the prime factorisation to find the greatest common divisor and least common multiple.
2 мин чтения
What a square root is, the perfect squares to know, how to simplify surds such as √180, and how to estimate roots like √65 without a calculator.
5 мин чтения
What an equation is, what its solution means, and how to solve equations step by step — from one-step equations to fractions and two variables.
1 мин чтения
Use inverse operations to get the unknown on its own, keep the equation balanced, and always check your answer.
2 мин чтения
Factorising, completing the square, the quadratic formula and the discriminant — and how to tell which method to use.
1 мин чтения
What slope measures, how to find it from two points, and how to write a line as y = mx + b.
4 мин чтения
How to simplify radicals by taking out perfect-square factors, what simplest radical form means, and how to simplify radical expressions — with checked examples.
2 мин чтения
What a rational equation is, how to solve rational equations by multiplying by the lowest common denominator, and why every answer must be checked.
3 мин чтения
The steps for factoring polynomials — common factor first, then two, three or four terms — with worked examples, each checked by multiplying back out.
3 мин чтения
Solving inequalities like equations — with one extra rule — and showing the answer on a number line, in interval notation and as a shaded region.
2 мин чтения
A solution is a value that makes an equation true. How to check one, and examples with one solution, no solution, all real numbers and two solutions.
2 мин чтения
A five-step method for solving word problems, the key words that turn into maths, and worked examples — ages, consecutive numbers, discounts and tickets.
2 мин чтения
Three ways to graph an equation — a table of values, slope and intercept, and key points of a parabola — with worked examples and how to match a graph to its equation.
3 мин чтения
Function notation, how to graph a function from its formula, how to find its domain and range, and how composite functions such as f(g(x)) work.
2 мин чтения
What a polynomial is, how to simplify and expand polynomials, and how to solve polynomial equations by factoring — with checked examples.
2 мин чтения
What rational expressions are, their excluded values, and how to simplify, multiply, divide, add and subtract them — then solve rational equations.
2 мин чтения
A literal equation has several letters. Solving it means isolating one of them — the same moves as an ordinary equation, with letters instead of numbers.
1 мин чтения
How to simplify the following kinds of expression: like terms, brackets, exponents and complex fractions (a fraction inside a fraction), each with checked examples.
1 мин чтения
The questions that say “find x” — equations, angles on a line, triangle angles, Pythagoras and similar shapes — and the one idea behind all of them.
2 мин чтения
How to find the solution to a system of equations three ways, then how to graph a system of inequalities: boundary lines, shading and the overlap.
1 мин чтения
How a² + b² = c² finds a missing side of any right triangle, plus the triples worth remembering.
1 мин чтения
Area formulas for rectangles, triangles, trapeziums and circles — and why the triangle formula has a half in it.
2 мин чтения
The formula for the area of a trapezium (a trapezoid in the US), why it works, and worked examples — including finding a missing height or side.
2 мин чтения
Scalene, isosceles and equilateral triangles — how to tell them apart, their angles, and how to find their area, including the area of an equilateral triangle.
1 мин чтения
Is a square a quadrilateral? Yes — and a rectangle, a rhombus and a parallelogram. How the family fits together, plus polygon angle sums and areas.
1 мин чтения
How to find the volume and surface area of a triangular prism, and the volume of cylinders and cones — one idea (area of the cross-section × length) behind most of them.
1 мин чтения
The three trig ratios, the two special triangles that give exact values, and how degrees relate to radians.
1 мин чтения
Three ways to describe a typical value, two ways to describe how spread out data is, and when to use each.
2 мин чтения
Three statistics skills that come up again and again: turning a z-score into a percentile, finding quartiles in a data set, and counting with the combination formula.
1 мин чтения
A derivative is the slope of a curve at a point. The power rule lets you differentiate any polynomial in one line.
2 мин чтения
How to find the determinant of a matrix: the ad − bc rule for 2×2, cofactor expansion for 3×3, a shortcut for triangular matrices, and what a zero determinant tells you.
2 мин чтения
How to solve percentage problems of all three kinds — a percentage of an amount, one number as a percentage of another, and percentage change — with checked examples.
1 мин чтения
Simplify ratios, share amounts in a ratio, and solve proportions — the maths behind recipes, maps and scale models.
Решите .
Каждый урок устроен так: по одному маленькому шагу и проверенный ответ.
Разбейте каждую тему на маленькие шаги, которые вы уже знаете. Уроки делают это за вас — например, квадратные уравнения начинаются с разложения на множители, а уже потом идёт формула корней.
Примеры заново решаются математическим движком или калькуляторами Sumzo в автоматических тестах, поэтому неверный ответ обнаруживается до публикации урока.
Нет. Все уроки можно читать бесплатно. Аккаунт только сохраняет прогресс в практике.