Brackets are symbols that are used to group parts of mathematical expressions together.

There are a number of different types of brackets. These include:

• parentheses (round brackets): \( (\;)\)
• square brackets: \([\;]\)
• squiggly brackets: \(\{\;\}\)
• angle brackets: \(\langle\;\rangle\)

When you are evaluating expressions with brackets, you need to always make sure that the brackets around the part of the expression you are working on match up. You should always work from the innermost brackets outwards.

For example, \([(2 + 4) \div 3] \times (2 + 7) = [6 \div 3] \times 9 = 2 \times 9 = 18.\).

The parentheses group the \(2\) and \(4\) together, and the \(2\) and \(7\) together. These should be evaluated first, because they are the innermost brackets. The square brackets group the result of \((2 + 4)\) and the \(3\) together.