An introduction to solving variable multiplication and division equations that uses fact families as the starting point. These pages make explicit the Part-Part-Whole relationship between the three numbers in an equation.
Emphasis is on the known, rather than the unknown, numbers. Once students understand the patterns for all addition and subtraction equations, they can easily and intuitively place the numbers within the appropriate expression to solve the equation. This also minimizes students’ tendency to solve equations ”backwards.”
This allows us to teach students to solve any variable equations without resort to multiple steps as are needed using the inverse operation procedure.
Students need some familiarity with fact families. An introduction to variables is helpful but not essential.
Common Core Standards:
3.OA.4: “Determine the unknown whole number in a multiplication or division equation relating three whole numbers.”
3.OA.5: “Apply properties of operations as strategies to multiply and divide…”
3.OA.6: “Understand division as an unknown-factor problem.”
Subject: Math, Algebra, Mental Math, Equations
Level: Grades 3 – 4
Length/Duration: 9 pages of student work, 2-3 days
Type of Resource: Instructional unit with students relating fact families to the solving of variable equations.
Answer Key: included
A Smart Notebook 14 file is also included.