This Fluency Activity is a part of the Lesson 14, Unit 4, Grade 1. This fluency activity reviews how to use the Level 3 strategy of making ten to add two single-digit numbers. In today's lesson, students learn how to apply this strategy when adding a one-digit number to a two-digit number. Carefully selecting pairs for collaborative work is essential to achieving expected outcomes. Some lessons lend themselves to groupings of students with similar skill sets, while others work better when students are heterogeneously grouped. Some students might benefit from the opportunity to work independently and share with the teacher or another pair after they have completed the task Assign partners of equal ability.