Unit 4, Lesson 11
Add Tens to 2-Digit Numbers
Grade 1
Preparation
Lesson Narrative
In previous lessons, students added and subtracted multiples of 10 from other multiples of 10. In this lesson, students reason about the value of expressions where both addends are two-digit numbers—one addend is a multiple of 10 and the other is not. Students use and explain methods that make sense to them and show their understanding about what the two digits in a two-digit number represent (MP3, MP7).
This lesson has a Student Section Summary.
- Action and Expression
- MLR8
- Explain (orally) strategies for adding two-digit numbers and a multiple of 10.
- Find the digit that makes an equation representing adding two-digit numbers and a multiple of 10 true.
- Let’s add tens to 2-digit numbers.
Required Materials
Required Preparation
None
Suggested Centers
NoneTeacher Reflection Questions
What methods did your students use to add tens to two-digit numbers? Which methods surprised you, and which did you expect?