” 90 − 10 ÷ 2 + 20 = ? Solution: According to the order of operations (division before addition and subtraction): First, calculate the division: 10 ÷ 2 = 5 Substitute the result back into the expression: 90 − 5 + 20 Solve from left to right: 90 − 5 = 85 85 + 20 = 105 Final Answer:

105 Many people incorrectly get 100 because they subtract first (90 − 10 = 80), but division must be performed before subtraction.