Faculty of Mathematics
Waterloo, Ontario N2L 3G1
Grade 7 & 8 Math Circles
October 8/9, 2013
When evaluating mathematical expressions it is important to remember that there is only
one right answer. Because of this, there is a strict set of rules that must be followed by all
mathematicians so that we can all agree and understand why an answer is correct.
Order of Operations
When working on more complicated mathematical expressions that involve multiple opera-
tions and many steps it is very important to do the math in the right order to ensure that
you get the right answer.
What is the right order?
1. Begin by simplifying everything inside of brackets.
2. Evaluate anything with exponents.
3. Starting from the left, work out all of the multiplication and division, whichever
4. Starting from the left, ﬁnish by evaluating all of the addition and subtraction,
whichever comes ﬁrst.
This can be summarized with the acronym BEDMAS:
Remember that division and multiplication are evaluated in the same step, even though
D appears before M in the acronym; division is no more important than multiplication.
Similarly, addition is no more important than subtraction.