Warm-Up 1
Day 8: Expressions and Equations
Write expressions, evaluate expressions, and solve simple equations.
Student Goal
I can use variables to write and solve simple math problems.
Why It Matters
Expressions and equations help students represent unknowns, patterns, and real-world situations in 7th grade math.
Warm-Up
Warm-Up 2
Which has an equals sign?
Warm-Up 3
Solve m + 6 = 10.
Short Lesson
Standard Focus
NC.7.EE: Expressions and Equations
Student-Friendly Standard Goal
I can write, evaluate, solve, and check simple expressions and equations.
- An expression is a math phrase, such as x + 5. It does not have an equals sign.
- An equation says two expressions are equal, such as x + 5 = 12.
- To solve an equation, find the value that makes the equation true. Then substitute it back to check.
Guided Examples
Guided Example 1
Solve and Check
Solve x + 9 = 22.
Step 1
x + 9 = 22
What operation will undo plus 9?
Guided Example 2
Write an Expression
A movie ticket costs 8 dollars. Write an expression for the cost of t tickets.
Step 1
t tickets
What does the variable represent?
Practice
Problem 1
Evaluate 2x + 1 when x = 5.
Problem 2
Which is an expression?
Problem 3
Solve y - 4 = 9.
Problem 4
True or false: a = 6 is a solution to a + 3 = 9.
Problem 5
A notebook costs d dollars. Which expression shows the cost of 4 notebooks?
Reflection
How are you feeling about today's skill?
Optional reflection: Why is checking a solution helpful?