Using What You Know

Students add a two-digit number and a one-digit number by decomposing an addend to make a ten and adding the remaining ones. Note: Activity 1 was updated in the Teacher Edition PDF and in the Teacher Presentation Screens on 1/12/2026.

By Amplify Classroom

Grades: 1st Grade

Subject: Math

Learning goals: Today’s Goals • Add a two-digit number and a one-digit number using place value understanding to compose a ten when necessary. • Language Goal: Explain how to find the amount of ones that could be added to a two-digit number to get to the next multiple of ten. (Speaking and Listening) Materials Lesson Resources: Activity 1 PDF, Graphic Organizer PDF, Tens and Ones Mat (optional); Manipulative Kit: connecting cubes (optional); Classroom materials: markers, Words to Describe Addition Strategies chart (from prior lessons)