Order of Operations

Why do we need to do our problems in a certain order?

Well, that’s a great question. If we didn’t have an agreed upon way of approaching a problem, when it requires multiplication, division, addition, etc. we would get different answers for the same problem.

3 * 7 - 8 - 4 = If I subtracted 7 - 8, first, I would get - 1. Then if I subtracted 4, I would get - 5, - 5 * 3 = -15

3 * 7 - 8 - 4 = If I multiplies 3 * 7, first, I would get 21. Then 21 - 8 = 13, and 13 - 4 = 9 (which is the correct answer)

If this were your bank account, you would want to make sure there is an agreed upon way to add, subtract, multiply and divide and not that it could simply be done anyway someone chose. This comes into play in many different situations, so it is a great idea to have an order of operations, in terms what should be don first.

PEMDAS

Operations inside parentheses should be done first.

Exponents should be done next.

Multiplication and division should be done next.

Finally, you do subtraction and addition last. When there are multiple operations to be done, on the same level, work from left to right to get the correct answer.