This short equation is a simple test of the order of operations.
The expression is 50 − 10 × 0 + 3. Multiplication comes before addition and subtraction, so start with 10 × 0. That equals 0.
The expression then becomes 50 − 0 + 3. Working from left to right gives 50 + 3.
Answer: 53.
The zero is what makes this puzzle deceptive. If you subtract first, you can easily end up with the wrong result. Following the normal order of operations makes the answer straightforward.


