David Tampier5,925 Points
There should be a mention of using brackets for ordering.
in my opinion a key missing information
Steven Parker186,663 Points
If by "brackets" you mean "parentheses" (sometimes called "round brackets" in the UK), they are not necessary in simple expressions. Even in complex expressions they would typically only be used when it is necessary to change the default precedence of evaluation. This concept was probably considered beyond the scope of this introductory-level beginner course.