NC.3.OA.8

Solve two-step word problems using addition, subtraction, and multiplication, representing problems using equations with a symbol for the unknown number.

Step 1: Lesson Standards & Learning Goals

Unpacking Clarification

This standard calls for students to represent problems using equations with a letter (variable) to represent unknown quantities. Students should be able to write and solve an equation when given a context. Students are expected to work with equations in which unknowns are in all positions.
The size of the numbers should be limited to related 3rd-grade standards.
- Tasks that include addition and subtraction should include numbers within 1,000 (NC.3.NBT.2).
- Tasks including multiplication are limited to either single digit factors (NC.3.OA.1, NC.3.OA.7) or multiples of 10 between 10 and 90 (NC.3.NBT.3).

Sample Essential Questions

How can two-step word problems be represented using equations with variables to represent the unknown numbers?
How can I create an equation to represent a two-step word problem?
How can equations help solve real-word problems?

Vocabulary

addition
compose
decompose
difference
equation
factor
inverse operation
multiplication
multiples
operation
position
quantity
subtraction
sum
unknown
variable

Students will be able to...

Write an equation with a symbol or letter (variable) standing for the unknown quantity.
Solve equations with the unknown in different positions.
Solve two-step word problems involving addition, subtraction, and multiplication.