# Center

What’s Behind My Back (K–2)

## Stage 1: Show 2 Parts

### Narrative

Students begin with a tower of 5–10 connecting cubes. They break apart the tower and represent the two parts with a drawing and an expression.

## Stage 2: 10 cubes

### Narrative

Students work with 10 cubes. One partner snaps the tower and puts one part behind their back and shows the other part to their partner. Their partner figures out how many cubes are behind their back.

This stage has two different recording sheets, one for kindergarten and another for grade 1. Be sure to use the appropriate recording sheet with students.

On the kindergarten recording sheet, students draw or color the connecting cube tower to show the two parts that the tower broke into and fill in an equation to show the total number of connecting cubes in the tower and the two parts that the tower was broken into.

On the grade 1 recording sheet, students record an addition equation with a blank to represent the missing cubes.