Lesson plan

6. Three-digit addition with regrouping (A)

teaches Common Core State Standards CCSS.Math.Content.2.NBT.B.7 http://corestandards.org/Math/Content/2/NBT/B/7
teaches Common Core State Standards CCSS.Math.Content.2.NBT.B.9 http://corestandards.org/Math/Content/2/NBT/B/9
teaches Common Core State Standards CCSS.Math.Practice.MP1 http://corestandards.org/Math/Practice/MP1
teaches Common Core State Standards CCSS.Math.Practice.MP8 http://corestandards.org/Math/Practice/MP8
Quick assign

You have saved this lesson plan!

Here's where you can access your saved items.

Content placeholder

or to view additional materials

You'll gain access to interventions, extensions, task implementation guides, and more for this lesson plan.

Lesson objective: Add two three-digit numbers involving regrouping 10 ones to make a new ten, and/or 10 tens to make a new hundred. 

This lesson provides an opportunity for students to apply their knowledge and understanding of three-digit addition with regrouping to a mathematical situation. Students are asked to validate or invalidate Dev's statement that the problem 496 + 404 only involves regrouping in the ones place.

Key Concept students will use: 

  • Addition strategies (such as regrouping) used with two-digit numbers can be used with three-digit numbers.

Skills students will use:

  • Add numbers within 1,000 using knowledge of place value and properties of operations
  • Add numbers within 100 using knowledge of place value (Grade 2, Unit 1)
  • Represent three-digit numbers in different but equivalent ways (Grade 2, Unit 6)
  • Understanding ten ones make a ten (Grade 1, Unit 1)

Students engage in Mathematical Practice 8 (Look for and express regularity in repeated reasoning) as they solve three-digit addition problems using previously learned strategies. Students will also apply regrouping strategies from two-digit addition to three-digit addition. Base ten blocks, number lines, and strategies related to place value will support students' understanding in this lesson.

Key vocabulary: 

  • base ten blocks
  • compose
  • decompose
  • digit
  • equivalent
  • hundreds
  • number line
  • ones
  • place value
  • regroup
  • tens