Lesson 10

Write Expressions and Equations to Represent Arrays

Lesson Purpose

The purpose of this lesson is for students to write equations to show the sum of the rows or columns of an array.

Lesson Narrative

In a previous lesson, students matched arrays to expressions with equal addends. In this lesson, students write equations with equal addends to represent an array as the sum of the number of objects in each row or the sum of the number of objects in each column.
  • Action and Expression
  • MLR2

Learning Goals

Teacher Facing

  • Represent the number of objects in each column or in each row of an array using equal addend equations.

Student Facing

  • Let’s write equations to represent arrays.

Required Materials

Materials to Gather

Required Preparation

CCSS Standards

Addressing

Lesson Timeline

Warm-up 10 min
Activity 1 15 min
Activity 2 20 min
Lesson Synthesis 10 min
Cool-down 5 min

Teacher Reflection Questions

What connections did students make between the structure of an array and the structure of the addition expressions they wrote? What questions did you ask to help make the connections more visible?

Suggested Centers

  • Write Numbers (1–2), Stage 4: Skip Count by 2, 5, and 10 (Addressing)
  • Target Numbers (1–5), Stage 7: Subtract Hundreds, Tens, or Ones (Supporting)

Print Formatted Materials

For access, consult one of our IM Certified Partners.

Additional Resources

Google Slides

For access, consult one of our IM Certified Partners.
PowerPoint Slides

For access, consult one of our IM Certified Partners.