# 6.6 Expressions and Equations

### Lesson 1

• I can tell whether or not an equation could represent a tape diagram.
• I can use a tape diagram to represent a situation.

### Lesson 2

• I can match equations to real life situations they could represent.
• I can replace a variable in an equation with a number that makes the equation true, and know that this number is called a solution to the equation.

### Lesson 3

• I can compare doing the same thing to the weights on each side of a balanced hanger to solving equations by subtracting the same amount from each side or dividing each side by the same number.
• I can explain what a balanced hanger and a true equation have in common.
• I can write equations that could represent the weights on a balanced hanger.

### Lesson 4

• I can explain why different equations can describe the same situation.
• I can solve equations that have whole numbers, fractions, and decimals.

### Lesson 5

• I understand the meaning of a fraction made up of fractions or decimals, like $\frac{2.1}{0.07}$ or $\frac{\frac45}{\frac32}$.
• When I see an equation, I can make up a story that the equation might represent, explain what the variable represents in the story, and solve the equation.

### Lesson 6

• I can use an expression that represents a situation to find an amount in a story.
• I can write an expression with a variable to represent a calculation where I do not know one of the numbers.

### Lesson 7

• I can solve percent problems by writing and solving an equation.

### Lesson 8

• I can explain what it means for two expressions to be equivalent.
• I can use a tape diagram to figure out when two expressions are equal.
• I can use what I know about operations to decide whether two expressions are equivalent.

### Lesson 9

• I can use a diagram of a rectangle split into two smaller rectangles to write different expressions representing its area.
• I can use the distributive property to help do computations in my head.

### Lesson 10

• I can use a diagram of a split rectangle to write different expressions with variables representing its area.

### Lesson 11

• I can use the distributive property to write equivalent expressions with variables.

### Lesson 12

• I can evaluate expressions with exponents and write expressions with exponents that are equal to a given number.
• I understand the meaning of an expression with an exponent like $3^5$.

### Lesson 13

• I can decide if expressions with exponents are equal by evaluating the expressions or by understanding what exponents mean.

### Lesson 14

• I know how to evaluate expressions that have both an exponent and addition or subtraction.
• I know how to evaluate expressions that have both an exponent and multiplication or division.

### Lesson 15

• I can find solutions to equations with exponents in a list of numbers.
• I can replace a variable with a number in an expression with exponents and operations and use the correct order to evaluate the expression.

### Lesson 16

• I can create tables and graphs that show the relationship between two amounts in a given ratio.
• I can write an equation with variables that shows the relationship between two amounts in a given ratio.

### Lesson 17

• I can create tables and graphs to represent the relationship between distance and time for something moving at a constant speed.
• I can write an equation with variables to represent the relationship between distance and time for something moving at a constant speed.

### Lesson 18

• I can create tables and graphs that show different kinds of relationships between amounts.
• I can write equations that describe relationships with area and volume.

### Lesson 19

• I can create a table and a graph that represent the relationship in a given equation.
• I can explain what an equation tells us about the situation.