Lesson 4

The purpose of this lesson is for students to add and subtract within 20 in a way that makes sense to them.

The work in this lesson builds from grade 1, where students add and subtract within 20 with different strategies. This is a chance to formatively assess how students find sums and differences in this range. Connecting cubes organized in towers of 10 and singles should be made available for students to use, however encourage students not to use them if they don’t need them. By the end of grade 2, students must fluently add and subtract within 20.

Math Community
Tell students that, at the end of the lesson, they will be asked to identify specific examples of norms they experienced as they did math.

By the end of grade 2, students must be fluent with addition and subtraction within 20, including knowing all sums of 2 one-digit numbers by memory. What did you learn about your students during today’s activities that will help you prepare all students to meet this standard?