Lesson objective: Understand that one way to perform addition is to put groups together and count to find the total amount.

Students bring prior knowledge of counting by ones to find how many, and finding one more from K.CC.1 and K.CC.4b. This prior knowledge is extended to adding within five as students begin to understand the operation of addition and the impact it has on numbers. A conceptual challenge students may encounter is understanding that addition is combining groups together to find the total amount, not placing numbers next to each other.

The concept is developed through work with a 5-frame and the use of precise mathematical vocabulary, which helps students easily count two sets to add them together and understand what the operation of addition means.

This work helps students deepen their understanding of operations because when students are able to connect counting to addition, they are able to understand how we can use mathematics strategically to manipulate numbers for a specific purpose.

Students engage in Mathematical Practice 1 (Students will make sense of problems and persevere in solving them) as they begin to explore how the operation of addition is performed and how it affects numbers.

**Key vocabulary:**

- addition
- altogether
- greater/more
- together
- total

**Special materials needed:**

- additional practice sheets
- manipulatives, if desired
- pencils