
Ontario Curriculum Expectation:
6.C2.2 evaluate algebraic expressions that involve whole numbers and decimal tenths.
When we evaluate an expression, we need to follow the order of operations.
1. Brackets
2. Multiplication or Division
3. Addition or Subtraction
Evaluate 9(x − y) − 4 when x = 6 and y = 4.
Put the values of x and y into the expression:
9(x − y) − 4
= 9(6 − 3) − 4
= 9(3) − 4
= 27 − 4
= 23
When there is no sign between a bracket and another value, it means multiplication will be used with two values. But remember to find the value inside the bracket first.
9(6 − 3) means 9 × (6 − 3)
= 9 × (6 − 3)
= 9 × 3
= 27
(10 − 9) (6 − 3) means (10 − 9) × (6 − 3)
= (10 − 9) × (6 − 3)
= 1 × 3
= 3