Lesson 7
What is an Array?
Lesson Purpose
Lesson Narrative
In the first section of this unit, students determined whether a group of objects was odd or even by organizing them in pairs or putting them into 2 equal groups.
In this lesson, students describe the structure of an array. They describe the number of objects in each row of an array and learn that the total number of objects in an array can be determined by finding the sum of the number of objects in each row. Although students may describe many features of the arrays in the lesson, the focus is on describing the rows of the array. They attend to the number of rows, the number in each row, and the total number of objects. In the next lesson, students will be encouraged to describe the columns of an array and will use this term in future lessons.
 Engagement
Learning Goals
Teacher Facing
 Describe an array as an arrangement of objects into rows with an equal number of objects in each row.
Student Facing
 Let’s learn about arrays.
Required Materials
Materials to Gather
Required Preparation
Activity 1:

Create containers with 6, 7, and 9 counters for each group of 2.
Lesson Timeline
Warmup  10 min 
Activity 1  20 min 
Activity 2  15 min 
Lesson Synthesis  10 min 
Cooldown  5 min 
Teacher Reflection Questions
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)