Grade 4 - Progress in Mathematics

Order of Operations

5-15

First multiplyand divide

from left to right.

Then addand subtract

from left to right.

Tim and To m were given this problem to solve.

6 
 54  2  4  5 n

Tim did this: To m did this:

6 
 54  60 54  2  27

60  2  30 4  5  20

30  4  26 6 
 27  33

26  5  130 33  20  13

Whose answer was correct?

Tom’s answer was correct.

He used the mathematical rules

called the order of operations.

These are the rules for the

order of operations:


Firstmultiply or divide.

Work in order from left to right.


Thenadd or subtract.

Work in order from left to right.

6 
 54  2  4  5 n 6 
 27  20  13

Study these examples.

100  6  7  2 x 3  4  6 
 5  5 a

100  42  2 x 12  6 
 5  5 a

100  21  79  6 72 
 1  73

8204-6_192-193 10/4/07 7:25 AM Page 192