Lesson 4
More Work with 1 and 2
Lesson Purpose
The purpose of this lesson is for students to subtract 1 or 2 within 10.
Lesson Narrative
This builds on the previous lesson where students considered the number sequence to support them in adding 1 or 2. When students see that subtracting 1 or 2 from any number is the same as counting one or two less, or counting back one or two, they are observing an important structure of the count sequence (MP7, MP8).
Math Community
Tell students that, at the end of the lesson, they will be asked to identify specific actions from their “Doing Math” list (both teacher and student sections) they personally experienced during the lesson today.
 Representation
 MLR8
Learning Goals
Teacher Facing
 Subtract within 10, given expressions in which 1 or 2 is subtracted, in a way that makes sense to them.
Student Facing
 Let’s subtract 1 or 2.
Required Materials
Required Preparation
Activity 1:

Each group of 2 needs a set of number cards 0–10.

Each group of 2 needs a Five in a Row game board from the previous lesson.
Activity 2:
 Counting Collections, Stage 1
 Number Race, Stage 3
 Check it Off, Stage 1
 Five in a Row: Addition and Subtraction, Stages 1 and 2
Lesson Timeline
Warmup  10 min 
Activity 1  20 min 
Activity 2  20 min 
Lesson Synthesis  10 min 
Cooldown  0 min 
Teacher Reflection Questions
What strategy did most students use in their work today? What surprised you about student thinking?