Why is it important to use the order of operations when evaluating an algebraic expression?

Answer 1

(B)rackets

(O)rder

(D)ivision

(M)ultiplication

(A)ddition

(S)ubtraction

According to BODMAS, multiplication should always be done before addition, therefore 17 is actually the correct answer according to BODMAS and will also be the answer which your calculator will give if you type in 2 + 3 x 5 .

I am assuming that you know what everything in BODMAS means apart from "Order". Order is actually a poor word to use here "Power" would be much better though BPDMAS doesn't quite have the same ring to it!

Order means anything raised to the power of a number.

You may have heard of Einstein's famous equation E = mc2 here it can be said that c is raised to the power 2, or c has order 2 or c is squared (they all mean the same thing!).

Here's an example to show how to use all the features of BODMAS:

Explain the answer that a calculator would give to the calculation 4 + 70/10 x (1 + 2)2 - 1 according to the BODMAS rules.

Brackets gives 4 + 70/10 x (3)2 - 1

Order gives 4 + 70/10 x 9 - 1

Division gives 4 + 7 x 9 - 1

Multiplication gives 4 + 63 - 1

Addition gives 67 - 1

Subtraction gives 66

THE PART OF BODMAS MOST OFTEN FORGOTTEN

It is quite common for people to forget that brackets always come first - which means you can calculate the answer of whatever is in the brackets before you attempt to calculate the rest of the problem.

Once you've worked out everything in the brackets, normally these sort of problems become very easy!