Lesson 12 Subtract From a Teen Number

    • Let’s subtract and add within 20.

Warm-up Choral Count: By Ten

Count by 10, starting at 2.

What patterns do you see?

Activity 1 Noah’s Collection

Noah likes to collect game pieces.
He has 19 game pieces arranged like this in his bin.

Two ten frames with connecting cubes. 3 rows, full. Bottom row, 4 cubes.

He takes out 8 game pieces to play with.
How many game pieces are left in the bin?
Show your thinking using drawings, numbers, or words.

Equation:

Activity 2 Addition and Subtraction Equations With Teen Numbers

 double 10-frame represents 17 + 3 =20

Find the number that makes each equation true.
Be ready to explain your thinking in a way that others will understand.

Activity 3 Introduce Shake and Spill: Cover

Practice Problem

Problem 1

Find the number that makes each equation true.