Five-Minute Check (over Lesson 5–7)
Main Idea and Vocabulary
Example 1:Addition Equations
Example 2:Subtraction Equations
Example 3:Write and Solve Equations
• I will write and solve addition and subtraction equations.
• defining the variable
Addition Equations
x + 8 = 15
Solve x + 8 = 15.
7 + 8 = 15
Answer: So, x = 7. The solution is 7.
You know that 7 + 8 is equal to 15.
1. A
2. B
3. C
4. D0% 0%0%0%
A. 4
B. 5
C. 9
D. 15
Solve x + 5 = 9.
Subtraction Equations
Solve 7 – x = 4.
7 – x = 4 Write the equation.
THINK 7 minus what number is equal to 4?
7 – 3 = 4 You know that 7 minus 3 is 4.
Answer: So, x = 3. The solution is 3.
1. A
2. B
3. C
4. D0% 0%0%0%
A. 3
B. 4
C. 5
D. 6
Solve 10 – x = 6.
Write and Solve Equations
Tim bought a book and a magazine at the bookstore. He spent $9. If a magazine costs $3, how much did the book cost?
Words
Variable
Expression
Cost of the book plus cost of the magazine is $9.
Let b represent the cost of the book.
b + 3 = 9
Write and Solve Equations
b + 3 = 9 Write the equation.
THINK What number plus 3 is equal to 9?
6 + 3 = 9 Replace b with 6 to make the equation true.
Answer: So, b = 6. The cost of the book is $6.
To check your solution, replace the variable with 6. Does this make the right side of the equation equal to the left side?
Check b + 3 = 9 Write the equation.
Replace b with 6.
9 = 9 Simplify. The solution is correct.
6 + 3 = 9?
Write and Solve Equations
1. A
2. B
3. C
4. D0% 0%0%0%
A. $2
B. $3
C. $4
D. $5
Marie bought a candy bar and a soda at the store. She spent $5. If the candy bar cost $2, how much did the soda cost?
End of the Lesson
Five-Minute Check (over Lesson 5–7)
Image Bank
Math Tool Chest
Model Multiplication Equations
1. A
2. B
3. C
4. D0% 0%0%0%
(over Lesson 5–7)
A. 14
B. 1
C. 52
D. 2
Evaluate the expression.
13 – (6 × 2)
1. A
2. B
3. C
4. D0% 0%0%0%
(over Lesson 5–7)
A. 2
B. 7
C. 3
D. 8
Evaluate the expression.
6 + (6 ÷ 3)
1. A
2. B
3. C
4. D0% 0%0%0%
(over Lesson 5–7)
A. 4
B. 3
C. 2
D. 12
Evaluate the expression.
(6 + 6) ÷ 3
1. A
2. B
3. C
4. D0% 0%0%0%
(over Lesson 5–7)
A. 2
B. 4
C. 6
D. 18
Evaluate the expression.
(8 ÷ 4) × 3
1. A
2. B
3. C
4. D0% 0%0%0%
(over Lesson 5–7)
A. 4.3
B. 7
C. 2
D. 8
Evaluate the expression.
(8 ÷ 2) + (9 ÷ 3)