# Understand Parentheses

Videos and solutions to help Grade 3 students learn how to understand the function of parentheses and apply to solving problems.

Common Core Standards: 3.OA.3, 3.OA.4, 3.OA.5, 3.OA.7, 3.OA.1, 3.OA.2, 3.OA.6, 3.OA.8

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Lesson Plans and Worksheets for Grade 3

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New York State Common Core Math Module 3, Grade 3, Lesson 8

Application Problem

Richard has 2 cartons with 6 eggs in each. As he opens the cartons, he drops 2 eggs. How many unbroken eggs does Richard have left?

Note: This problem provides context for solving equations involving multiple operations, which is central to the Concept Development.

Concept Development

Part 1: Solve equations containing parentheses.

Part 2: Explore how moving the parentheses can change the answer in an equation.

Lesson 8 Homework

1. Solve.
a. 9 - (6 + 3) = ______
b. (9 - 6) + 3 = ______
c. ______= 14 - (4 + 2)
d. ______ = (14 - 4) + 2
e. ______ = (4 + 3) × 6
f. ______ = 4 + (3 × 6)
g. (18 ÷ 3) + 6 = ______
h. 18 ÷ (3 + 6) = ______

2. Use parentheses to make the equations true.
a. 14 - 8 + 2 = 4
b. 14 - 8 + 2 = 8
c. 2 + 4 × 7 = 30
d. 2 + 4 × 7 = 42
e. 12 = 18 ÷ 3 × 2
f. 3 = 18 ÷ 3 × 2
g. 5 = 50 ÷ 5 × 2
h. 20 = 50 ÷ 5 × 2
3. Determine if the equation is true or false.
a. (15 - 3) ÷ 2 = 6 Example: True
b. (10 - 7) × 6 = 18
c. (35 - 7) ÷ 4 = 8
d. 28 = 4 × (20 - 13)
e. 35 = (22 - 8) ÷ 5
4. Jerome finds that (3 × 6) ÷ 2 and 18 ÷ 2 are equal. Explain why this is true.
5. Place parentheses in the equation below so that you solve by finding the difference between 28 and 3. Find the answer.
4 × 7 - 3 =
6. Johnny says that the answer to 2 × 6 ÷ 3 is 4 no matter where the parentheses are. Do you agree?
Place parentheses around different numbers to show his thinking.

Lesson 8 Homework

1. Solve.
a. 9 - (6 + 3) = ______
c. ______= 14 - (4 + 2)
e. ______ = (4 + 3) × 6
g. (18 ÷ 3) + 6 = ______
5. Place parentheses in the equation below so that you solve by finding the difference between 28 and 3. Find the answer.
4 × 7 - 3 =
6. Johnny says that the answer to 2 × 6 ÷ 3 is 4 no matter where the parentheses are. Do you agree?
Place parentheses around different numbers to show his thinking.
Lesson 8 Homework Sample Solutions

2. Use parentheses to make the equations true.

a. 14 – 8 + 2 = 4

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