# Order of Operations

This is a complete lesson for third grade with teaching and exercises about the order of operations. The exercises only deal with parenthesis, addition, subtraction, and multiplication (not division). Students are encouraged to circle the first operation to be done in a bubble or balloon - that can make it fun! Lastly, they get to do a fun puzzle corner, figuring out which operations make the given equations true.

## Order of operations

1) First we calculate what is inside the  PARENTHESES ( ) .

2) Then, we MULTIPLY before adding or subtracting.

3) Lastly, we ADD and SUBTRACT from left to right.

Example.  4 × (2 + 3)

First we calculate 2 + 3 because it is inside the parentheses.

So, we get 4 × 5. That is 20.

1. Add and subtract. Remember the parentheses! Circle the operation that needs
to be done FIRST in a "bubble" or a balloon.

 a.   20 + 6 − 3  b.   20 + (6 − 3) c.   20 − 6 + 3  d.   20 − (6 + 3) e.  80 − 30 − (30 + 20)  f.  80 − (30 − 30) + 20

2. Calculate. Circle the operation to be done first. Parentheses → multiply → add/subtract.

 a.  3 + 5 × 2 b.  5 × (3 + 1) c.  4 × (4 − 2) d.  3 × 6 − 11 e.  25 − 5 × 2 f.   (3 − 2) × 6 g.   (4 + 2) × 2 h.   3 × 5 + 2 × 4 i.  50 − (7 − 2) × 4

3. Circle the operation to be done first in a “bubble”!

 a. 0 × 7 + 2
 b. 5 + 1 × 3
 c. 5 × (1 + 9)
 d. (10 − 5) × 4
 e. 55 + 0 × 3
 f. 8 × 2 − 12

4. Now watch carefully! You will need more steps.

 a.   3 × 4 − 2 × 3 b.   6 + 7 × (4 − 2) c.   2 × (5 + 4) + 5 d.   30 − 2 − 7 × 2

5. Solve. Write a number sentence for each problem. Don't just write the answer.

 a. Ten people are going to eat dinner. One of them is little Hannah. There are     two plates for everybody, except Hannah gets only one plate. How many plates     are on the table? b. In a little restaurant, there are five tables for two people and four tables     for four people. How many people can sit in the restaurant?

 Which operations will make the number sentences true?
 16 1 1 = 1535 5 4 = 15 10 5 2 = 20   5 7 6 = 41 3 4 5 6 = 29 9 3 5 2 = 17

You can make a game out of this. Make problems beforehand and use any board game with dice,
the rule being that you can roll the die only if you first answer the question right.

This lesson is taken from Maria Miller's book Math Mammoth Multiplication 1, and posted at www.HomeschoolMath.net with permission from the author. Copyright © Maria Miller.

#### Math Mammoth Multiplication 1

A self-teaching worktext for 3rd grade that covers multiplication concept from various angles, word problems, a guide for structural drilling, and a complete study of all 12 multiplication tables.