Lesson 7

Restemos dos dígitos

Lesson Purpose

The purpose of this lesson is for students to subtract a two-digit number from a two-digit number when a ten is decomposed when subtracting by place.

Lesson Narrative

In previous lessons, students learned that decomposing a ten is sometimes necessary when subtracting two numbers. Students used connecting cubes and base-ten blocks to represent their methods when subtracting a one-digit number from a two-digit number.

In the fist activity, students use methods that make sense to them to subtract and compare their methods with a partner. In the activity synthesis, students make connections across different methods and representations and consider which tools and representations work best for them. In the second activity, students use base-ten blocks to represent expressions and decompose a ten when subtracting by place.

Students should have access to connecting cubes and base-ten blocks throughout the lesson and the cool-down.

  • Representation

Learning Goals

Teacher Facing

  • Subtract a two-digit number from a two-digit number in a way that makes sense to them.

Student Facing

  • Hagamos restas con números de dos dígitos.

Required Materials

Materials to Gather

Materials to Copy

  • Using Blocks to Take Away, Spanish

Required Preparation

Activity 2:

  • Create a set of cards from the blackline master for each group of 4.

CCSS Standards

Addressing

Building Towards

Lesson Timeline

Warm-up 10 min
Activity 1 15 min
Activity 2 20 min
Lesson Synthesis 10 min
Cool-down 5 min

Teacher Reflection Questions

How are base-ten blocks and diagrams supporting students in showing what they understand about decomposing a ten when subtracting by place?

Suggested Centers

  • Capture Squares (1–3), Stage 3: Add within 20 (Addressing)
  • Five in a Row: Addition and Subtraction (1–2), Stage 6: Add within 100 with Composing (Addressing)
  • Target Numbers (1–5), Stage 4: Subtract Tens or Ones (Addressing)

Print Formatted Materials

Teachers with a valid work email address can click here to register or sign in for free access to Cool Down, Teacher Guide, and PowerPoint materials.

Student Task Statements pdf docx
Lesson Cover Page pdf docx
Cool Down Log In
Teacher Guide Log In
Teacher Presentation Materials pdf docx
Blackline Masters zip