Lesson 2
How Did You Add?
Lesson Purpose
The purpose of this lesson is for students to add 2 twodigit numbers, without composing a ten, using methods based on place value and make sense of equations that represent addition methods.
Lesson Narrative
In previous lessons, students added teen numbers and onedigit numbers. Students also added twodigit numbers and multiples of 10 and twodigit numbers and onedigit numbers without composing a ten. In this lesson, students are invited to add 2 twodigit numbers that are not multiples of 10 in a way that makes sense to them. Some students may attempt to write equations, but are not required to do so. The teacher draws diagrams and writes equations that match student thinking during the activity synthesis for students to interpret. Throughout the lesson, students explain their own methods, interpret others' methods, and connect different methods (MP3). Students notice different ways to make use of the baseten system to count on or add by place (MP7).
 Action and Expression
 MLR8
Activity 1: Find the Value
Learning Goals
Teacher Facing
 Add 2 twodigit numbers, without composing a ten, using methods based on place value.
 Make sense of equations that represent addition methods.
Student Facing
 Let’s add numbers and find matching equations.
Required Materials
Materials to Gather
Materials to Copy
 Five in a Row Addition and Subtraction Stage 5 Gameboard
Required Preparation
Lesson Timeline
Warmup  10 min 
Activity 1  15 min 
Activity 2  10 min 
Activity 3  15 min 
Lesson Synthesis  10 min 
Cooldown  0 min 
Teacher Reflection Questions
What connections did students make between the different methods shared? What questions did you ask to help make the connections more visible?
Print Formatted Materials
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Additional Resources
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