---
tags:
  - prealgebra
---

## Grouping symbols

We use parentheses to delimit the part of an expression we want evaluated first.
If grouping symbols are nested, evaluate the expression in the innermost pair of
grouping symbols first,

## Writing mathematical statements: placement of $=$

We only write one equals sign per line. For example, if we are resolving
parentheses:

$$ \begin{equation} \begin{split} 2 + \[3 + (4+5)\] = 2 + \[3 +9\] \\ = 2 + 12
\\ = 14 \end{split} \end{equation} $$

We call parentheses (`()`), brackets (`[]`) and braces `{}`) grouping symbols.
When groupings (say parentheses) are used, the expression inside any pair of
parentheses must be evaluated first.
