How old is Emily? At first glance, the question looks simple, but the answer depends on following the correct order of operations. Emily gives her age as the expression 80 − 40 ÷ 10 × 4, leaving us to determine what number it represents.

To solve it correctly, we use the standard PEMDAS/BODMAS rules. Multiplication and division come before addition and subtraction, and when multiplication and division appear together, they are calculated from left to right. So, we begin with 40 ÷ 10, which equals 4. The expression then becomes 80 − 4 × 4.

Next, multiplication must be completed before subtraction. Four multiplied by four equals 16, leaving us with 80 − 16. The final calculation is 80 minus 16, which gives 64. Therefore, according to Emily’s clever mathematical answer, she is 64 years old.

A common mistake is to simply work through the expression from left to right, starting with 80 − 40. That would produce a different result, but it ignores the standard order of operations. By applying the rules correctly, the calculation leads to 64, making that the intended answer to Emily’s age puzzle.