The purpose of this activity is for students to use what they know about making a ten to identify which addition expressions are equivalent to expressions. This matching task gives students opportunities to analyze equivalent expressions closely and make connections (MP2, MP7). Students should have access to double 10-frames and connecting cubes or two-color counters.

The Compare Stage 2 Addition Cards will be used again in a later lesson.

• “Vamos a crear un póster y a hacer un recorrido por el salón” // “We are going to create a poster and do a Gallery Walk.”

The purpose of this activity is for students to create a poster to show all the expressions equivalent to their assigned expression. Before the activity, assign each group an expression for which they will make a poster. Then students get into new groups of three, and each group visits three posters. Students consider what patterns they notice between the expressions on the poster. Students may notice there is a relationship between the addends of equivalent expressions. For example, when one addend decreases by 1, the other addend in the sum increases by 1 (MP7).

This activity uses MLR7 Compare and Connect. Advances: Representing, Conversing

• Display posters for , , and .
• “¿Qué patrones observaron cuando vieron los pósteres al recorrer el salón?” // “What patterns did you notice as you went from poster to poster?” (I saw that there was an expression with 9 on every poster. For example, is equivalent to . This is because I can take 1 from the 4 and give it to the 9.) To amplify student language and illustrate connections, follow along and point to the relevant parts of the displays as students speak.
• Record responses as equations (for example, ). 
• Record . “¿El mismo patrón está en otros pósteres?” // “Is the same pattern on other posters?” (Yes, it happened on . If I have , I can take 1 from the 3 and give it to the 9. Then I have .)

The purpose of this activity is for students to choose from activities that offer practice adding and subtracting within 10. Students choose from any of the previously introduced stages of the listed centers:

• Shake and Spill
• Compare
• Number Puzzles

• Display 9 red counters and cover 5 yellow counters with a cup.
• “Estamos jugando con 14 fichas. ¿Cuántas fichas amarillas hay debajo del vaso? ¿Cómo lo saben?” // “We are playing with 14 counters. How many yellow counters are under the cup? How do you know?”