Reflection: Student Ownership Introducing the Addition Algorithm - Section 1: Warm Up


There is great value in helping second graders learn to explain their thinking. I always encourage students to talk about how they solved a problem, what they were thinking, and what strategies they used to solve the problem. At first it was a struggle. Students would say, "I just did it," but they were so unaware of the how or why. 

Today, a parent came in to tell me how her child, who has been struggling with math, sat down and explained to her how you can take an addition problem that is written vertically and add the tens and then add the ones and put them together. The child said that you can check your work by finding the smiley face number that each number is close to and add them to see if the two answers were close. This child had internalize the process and was then able to really explain the process she was using, one that was based on place value reasoning.

It is a crucial skill that is worth taking the time to stress in each lesson that you teach. If a child knows what he/she is doing, to the point that they can explain it, they can apply that to future math experiences.

  Explaining Your Thinking
  Student Ownership: Explaining Your Thinking
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Introducing the Addition Algorithm

Unit 17: Getting Better at Addition and Subtraction
Lesson 8 of 12

Objective: SWBAT estimate the answer for a 2-digit addition problem and add when the numbers are in columns.

Big Idea: Students are able to add and subtract when numbers are presented horizontally. They add and subtract tens and ones with appropriate fluency. Today they will be introduced to adding two 2-digit numbers presented vertically.

  Print Lesson
Math, Number Sense and Operations, addition, addition algorithm, Operations
  45 minutes
100 0818
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