2. Golden Rule of Algebra:
Name________________________________________________ Date: ___/___/_____
Modeling Equations Lab
Objective: The purpose of this lab is to practice MODELING the process of solving an
equation. The concept of “balancing” will be emphasized.
Directions: Model each problem on your equation mats with the tiles. Then, record your work on this paper.
1. Solve: x + 3 = 5
Step 1: Model the problem on the scale below.
What do you need to do to isolate the variable? ______________________
Step 2: Place the negative tiles on the mat. Remember– whatever you add to one side,
you MUST add to the other side!
How many zero pairs do you have on each side? _____________
Step 3: Take away the zero pairs (indicate this by circling them). What’s left?
x = _____
Step 4: Check your answer by substituting answer back into original problem:
KEY: x + -
Golden Rule of Algebra:
Whatever you do to one side of an equation, you MUST do to the other side!!

3. 2. Solve: x – 2 = 5
Model the problem on the scale below:
What do you need to do to isolate the variable? _____________________________
Place the appropriate tiles on the mat to make zero pairs. How many zero pairs do you have on each side? __________________________________________________
Take away the zero pairs (indicate this by circling them).
Write your final answer: _____
Check your answer:
3. Solve: x – 4 = -3

4. 4. Solve: x + -4 = -2 5. Solve: x + 3 = -1
Model the problem on the scale below:
What do you need to do to isolate the variable? _____________________________
Place the appropriate tiles on the mat to make zero pairs. How many zero pairs do you have on each side? __________________________________________________
Take away the zero pairs (indicate this by circling them).
Write your final answer: _____
Check your answer:
5. Solve: x + 3 = -1

5. 6. Solve: x + 10 = -2 7. Solve: x – (-3) = -1
Model the problem on the scale below:
What do you need to do to isolate the variable? _____________________________
Place the appropriate tiles on the mat to make zero pairs. How many zero pairs do you have on each side? __________________________________________________
Take away the zero pairs (indicate this by circling them).
Write your final answer: _____
Check your answer:
7. Solve: x – (-3) = -1

6. Discussion Questions:
Why did we use a picture of a balance in our model?
2. What is the main goal when solving an equation?
3. Identify the main math property that we used while solving our equations.
Why are zero pairs (Inverse Property) necessary to solve an equation?
Write a rule that you can use to solve an equation like x + 3 = 2 without
using models.

7. Name:__________________________________________________________ Date:____/____/_______
EXIT TICKET
I fully participated in the lab today, completing every equation in the
packet.
A. True B. False (only completed a portion)
2. Model the below equation on the given mat. Show the entire process,
circling any zero pairs needed.
x + (-4) = -2
x = _____
3. How is the Inverse Property of Addition used when solving an equation?
In your own words, describe the Golden Rule of Algebra.
Identify one thing that you learned during today’s lab/ class discussion–
about the process of solving an equation.

8. Math-7 homework “Modeling Equations”
NAME:___________________________________________________________________________ DATE: _____/_____/__________
“Modeling Equations”
Draw tiles onto the below balance scales in order to model the following:
x + -3 = x = 1
3. x + (-2) = x – 4 = -2
x – (-2) = x – (-5) = 3
x = x + (-1) = -1
x = _____
x = _____
x = _____
x = _____
x = _____
x = _____
x = _____
x = _____