**Click here for the Spanish version: https://youtu.be/-ZtJk4AeEbU**

**In This Unit of Study…**

Students use rectangular arrays to work with repeated addition. Students explore this concept by using concrete models (counters, square tiles, and linking cubes) and by creating pictorial representations on grid paper. Based on the commutative property of addition (explored in first grade), students can add either the rows or the columns to find the total amount within an array. Students express the array by using equations. Arrays at this grade level are composed of up to 5 rows and up to 5 columns. This concept is a building block towards multiplication.

**B.E.S.T. Benchmarks:**

- MA.2.AR.3.2 Use repeated addition to find the total number of objects in a collection of equal groups. Represent the total number of objects using rectangular arrays and equations.

**Key Concepts:**

- I can use repeated addition to find the total number of objects in a collection of equal groups up to 25 and represent them arranged in rectangular arrays with up to 5 rows and up to 5 columns.
- I can write an equation to express the total as a sum of equal addends.