5.OA.A.1

Use parentheses, brackets, or braces in numerical expressions, and evaluate expressions with these symbols.

Evaluate expressions involving parentheses. See examples of () and [], but not {} (because curly brackets denote sets). Show students that subtractions can be replaced by additions and divisions can be replaced by multiplications. Here's an article to show you what I mean.

Notes: The standard talks about *brackets* and *braces* but doesn’t differentiate between the two. Khan Academy has examples using curly brackets, for example, {10 * 7}, but curly brackets have a special meaning, namely, to denote sets. Thus, I advise against the use of curly brackets.