# Math K-5: Foundations of Multiplication & Division

#### 2nd Grade Math

These annotated tasks were collected from second graders working with Module 6 Lesson 4 of the EngageNY materials. This module focuses largely on standard 2.OA.C.4:

2.OA.C.4: Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.

The students begin the module using manipulatives to create equal groups. Then they move to modeling the groups with drawings of objects and equations with equal addends. In this lesson, the students are asked to represent the equal groups with a tape diagram model and make the connection to repeated addition. The lessons that follow this lesson will move students toward working with arrays to represent the groups.

It is important to note that the students have previously learned some strategies for adding several equal numbers. They have used skip counting and grouping to create equations with fewer addends. For example, 2 + 2 + 2 + 2 can be simplified by skip counting by 2s or by grouping the 2s by pairs, changing to the less complicated sum of 4 + 4. The students were introduced to tape diagram models in previous modules while building a conceptual foundation for addition and subtraction of two-digit numbers. In this lesson, the students use the tape diagram model to develop conceptual understanding of repeated addition. Then the students complete the problem set (the annotated task) individually or with a partner. In this instance, the students did not debrief the task with the teacher.