Exponent and Parenthesis Traps

The trickiest PEMDAS mistake: forgetting that exponents bind tighter than multiplication. In -3 squared, the negative is not inside the exponent, so it equals -(9) = -9, not +9. Parentheses fix this: (-3) squared = 9. One missed parenthesis changes the sign.

Programming languages enforce PEMDAS too. When code computes price * quantity + tax, the multiplication happens first. But price * (quantity + tax) gives a different answer. Understanding operator precedence is not optional for anyone writing formulas.