(7) Inquiry Lab - Solve One Step Addition and Subtraction Equations

1. HOW can bar diagrams or
algebra tiles help you
solve an equation?
Course 2, Inquiry Lab before Lesson 6-1
Expressions and Equations

2. • 7.EE.4
Use variables to represent quantities in a real-world or mathematical
problem, and construct simple equations and inequalities to solve
problems by reasoning about the quantities.
• 7.EE.4a
Solve word problems leading to equations of the form px + q = r and p(x +
q) = r, where p, q, and r are specific rational numbers. Solve equations of
these forms fluently. Compare an algebraic solution to an arithmetic
solution, identifying the sequence of the operations used in each
approach.
Mathematical Practices
1 Make sense of problems and persevere in solving them.
2 Reason abstractly and quantitatively.
3 Construct viable arguments and critique the reasoning of others.
5 Use appropriate tools strategically.
Course 2, Inquiry Lab before Lesson 6-1 Common Core State Standards © Copyright 2010. National Governors Association Center for
Best Practices and Council of Chief State School Officers. All rights reserved.
Expressions and Equations

3. Course 2, Inquiry Lab before Lesson 6-1
Activity 1
Continued

Expressions and Equations
In a recent year, 19 of the 50 states had a law banning the use of
handheld cell phones while driving a school bus. Determine how
many states did not have this law.
The bar diagram represents the total number of states and the
number of states that have passed a cell phone law. Fill in the
missing information.

4. Course 2, Inquiry Lab before Lesson 6-1
Activity 1
Continued

Expressions and Equations
In a recent year, 19 of the 50 states had a law banning the use of
handheld cell phones while driving a school bus. Determine how
many states did not have this law.
Write an equation from the bar diagram. Let x represent the
states that do not have a cell phone law for school bus
drivers.
19 + x = 50

5. Course 2, Inquiry Lab before Lesson 6-1
Expressions and Equations
In a recent year, 19 of the 50 states had a law banning the use of
handheld cell phones while driving a school bus. Determine how
many states did not have this law.
Use the work backward strategy to solve the equation. Since
19 + x = 50, x = 50 – 19. So, x = .
Check 19 + = 50 ✓
So, states did not have a law banning
the use of cell phones by bus drivers.

6. Course 2, Inquiry Lab before Lesson 6-1
Activity 2
Continued

Expressions and Equations
Solve x – 3 = –2 using algebra tiles.
Remember a 1-tile and a –1-tile combine to make a zero pair. You
can add or subtract zero pairs from either side of an equation
without changing its value.
Model the equation.

7. Course 2, Inquiry Lab before Lesson 6-1
Activity 2
Continued

Expressions and Equations
Solve x – 3 = –2 using algebra tiles.
Remember a 1-tile and a –1-tile combine to make a zero pair. You
can add or subtract zero pairs from either side of an equation
without changing its value.
Add three 1-tiles to the left side of the mat and _____________
1-tiles to the right side of the mat to form zero pairs on each side
of the mat.

8. Course 2, Inquiry Lab before Lesson 6-1
Expressions and Equations
Solve x – 3 = –2 using algebra tiles.
Remember a 1-tile and a –1-tile combine to make a zero pair. You
can add or subtract zero pairs from either side of an equation
without changing its value.
Remove all of the zero pairs from each side. There is _________
1- tile on the right side of the mat.
Therefore, x = . Check – 3 = –2 ✓

9. Course 2, Inquiry Lab before Lesson 6-1
HOW can bar diagrams or
algebra tiles help you
solve an equation?
Expressions and Equations