Unit 4, Lesson 16# Add ones and ones or tens and tens.

EngageNY 60 min(s)

In this lesson, students begin to focus on adding ones with ones or adding tens with tens. They recognize single-digit addition facts as they solve, for example, 15 + 2, 25 + 2, and 35 + 2. When adding 35 + 2, students see that they are adding 5 ones to 2 ones, while the tens remain unchanged, to make 3 tens 7 ones or 37. By contrast, when adding 12 + 20, students see that they are adding 2 tens to 1 ten to make 3 tens 2 ones or 32.