Lesson 19 Methods for Addition Within 20

    • Let’s add within 20.

Warm-up Number Talk: Related Expressions

Find the value of each expression mentally.

Activity 1 Lin, Han, and Kiran Add

Lin, Han, and Kiran are finding the value of .

Double ten frame. 8 red counters. 7 yellow counters.

Lin thinks about .

Han thinks about .

Kiran thinks about .

Explain how each student’s method works.
Show your thinking using drawings, numbers, or words.

Activity 2 How Did You Add?

  • Choose an addition card.

  • Each partner finds the value independently.

  • Each partner gives a signal when they are ready to explain their thinking.

  • Each partner shares their thinking.

  • Each partner writes the equation.

Choose your favorite equation.
Show how you found the value using drawings, numbers, or words.

Practice Problem

Problem 1

Find the value of each sum.
Show your thinking using drawings, numbers, or words.