Order of operations, letters and formulae

Work out expressions step by step in the right order. Then let a letter stand for a number and use formulae.

Guide

This studio follows Year 6: the order of operations (BIDMAS), simple formulae, and pairs of numbers that satisfy an equation such as a + b = 10.

BIDMAS: Brackets first, then Indices (powers), then Division and Multiplication from left to right, then Addition and Subtraction from left to right.

Tap the operation you want to do first. Each step writes a new line, as in an exercise book. A wrong order is allowed but recorded; use "Undo" to take a step back.

In algebra a letter such as n or a stands for a number. 2n means 2 × n: if n = 5, then 2n is 10, not 25.

A formula such as P = 4a works like a machine: the side of a square (a) goes in and the perimeter (P) comes out.