## Reflection: Connection to Prior Knowledge Solving Systems Using Elimination: An Intuitive Approach -- Day 1 of 2 - Section 1: Opening

This is one of my favorite tasks for solving systems of equations.  I love this task because students are asked to solve a series of problems that build on each other, using their intuitive reasoning rather than what they know about algebra. I recently presented this problem to a group of math teachers to work on and I had to remind them again and again NOT to write equations to represent the situations.  It was very hard for them to resist.  My students, on the other hand, usually seem thrilled to put algebra aside for a class period.  This lesson allows them to think through why two variables cancel each other out when we combine equations before they think about a system of equations. I found some of the math teachers I was working with to almost be surprised about how this works.  In the first problem, two kinds of the food already match up. But in the second problem, students have to think about doubling everything, even the total on the bill, to get two kinds of food to match up. I have found students who sometimes struggle in algebra to really thrive in explaining how these problems work intuitively. I really appreciate how this task surfaces conceptual understanding before showing students the skill of solving using elimination.

Making room for student intuition
Connection to Prior Knowledge: Making room for student intuition

# Solving Systems Using Elimination: An Intuitive Approach -- Day 1 of 2

Unit 3: Systems of Equations and Inequalities
Lesson 7 of 17

## Big Idea: Where is the difference in price? Students reasons through receipts in order to see the structure of solving systems using elimination.

Print Lesson
5 teachers like this lesson
Standards:
Subject(s):
Math, Algebra, Systems of Equations and Inequalities, systems of equations, solving systems of equations using elimination
50 minutes

### Amanda Hathaway

##### Similar Lessons

###### The Cell Phone Problem, Day 1
Algebra II » Rational Functions
Big Idea: Real world modeling of rational functions. Cell phone signal strength, can you hear me now?
Favorites(7)
Resources(20)
Fort Collins, CO
Environment: Suburban

###### Building Cat Furniture: An Introduction to Linear Programming
12th Grade Math » Matrices and Systems
Big Idea: Use Legos for an interactive introduction to linear programming!
Favorites(9)
Resources(24)
Troy, MI
Environment: Suburban

###### Graphing Linear Functions in Standard Form (Day 1 of 2)
Algebra I » Graphing Linear Functions
Big Idea: Students will analyze the importance of intercepts in linear function, and use them to graph lines that are in an unfamiliar format.
Favorites(45)
Resources(16)
Washington, DC
Environment: Urban