The purpose of this How Many Do You See is for students to subitize or use grouping strategies to describe the images they see. The images include 10-frames to elicit students' work when adding within 20. The images also encourage students to think about composing a ten by counting on. This is the focus of the activities later in the lesson.

• “¿En qué se parecen la segunda y la tercera imagen? ¿En qué son diferentes?” // “How are the second and third images alike? How are they different?” (In the second image all of the 10-frames are full, but in the third they are not.)

The purpose of this activity is for students to add a one-digit number and a two-digit number in a way that makes sense to them. 

Monitor for and select students with the following approaches to share in the Activity Synthesis:

• Start with 47, and then count on 8. 
• Start with 47, decompose the 8 into 3 and 5, make a new ten with 47 and 3, and then add the remaining 5. 
• Decompose 47 into 4 tens and 7 ones, add the ones, and then add the 4 tens. 

The approaches are sequenced from more concrete to more abstract to help students make sense of different approaches when it is possible to compose a new ten. Aim to elicit both key mathematical ideas and a variety of student voices, especially students who haven't shared recently

During the Activity Synthesis, the teacher represents student approaches with connecting cubes, so the new ten is visible to all students. 

The purpose of this activity is for students to practice adding a one-digit number and a two-digit number in a way that makes sense to them. Students may choose to use methods shared in the previous activity. Give half of the class one-digit numbers and the other half two-digit numbers. Students work in pairs to create a sum with a two-digit number and a one-digit number. In some problems, the sum will require composing a ten when adding ones to ones. Monitor for students who share ways they make a new ten with connecting cubes or drawings to share in the Activity Synthesis.

When students choose a method to add based on the pair of numbers they are adding, they make use of structure and apply regularity in reasoning (MP7, MP8). This could mean counting on when the one-digit number is small, adding the ones when there is no new ten, and adding on to make a ten if needed.

The purpose of this activity is for students to solve story problems that require adding a two-digit number and a one-digit number with composing a ten. This activity offers additional practice using methods discussed in the previous activities, while giving context for adding these quantities. Students share examples of when they have added or seen others add quantities like those they have been adding. This activity is optional because it provides practice solving story problems with numbers larger than 20, which is not an expectation of students in grade 1.