Module 2: Subtraction Strategies-Math 2A - Course Guide

Module Overview:

In this module, students will define the meaning of subtraction, solve simple subtraction sentences, and identify missing parts of a subtraction sentence. Students will define the counting-back subtraction strategy and solve subtraction sentences using the counting-back strategy. They will identify doubles to subtract and solve doubles subtraction facts using Unifix cubes and/or drawings. Students will define the parts and whole of addition and subtraction sentences, identify similarities between addition and subtraction sentences, identify the parts of a subtraction sentence and write subtraction sentences to represent pictures.

Module Materials:

Lesson # Lesson Title Material(s)
1 Subtraction Properties A bag of colored candies (M&M’s or Skittles) or counters;
2 Count Back to Subtract Counters;
3 Use Doubles to Subtract Dominoes with equal sides totalling 4, 6, 8, 10, 12; 20 Unifix cubes;
4 Relate Addition and Subtraction Counters;
5 Write Subtraction Sentences Counters, Crayons;

Module Objectives:

Lesson # Lesson Title Objective(s)
1 Subtraction Properties
1. Define the meaning of subtraction.
2. Solve simple subtraction sentences.
3. Identify missing parts of a subtraction sentence.
2 Count Back to Subtract
1. Define the counting-back subtraction strategy.
2. Solve subtraction sentences using the counting-back strategy.
3 Use Doubles to Subtract
1. Identify doubles to subtract.
2. Solve doubles subtraction facts using Unifix cubes and/or drawings.
4 Relate Addition and Subtraction
1. Define the parts and whole of addition and subtraction sentences.
2. Identify similarities between addition and subtraction sentences.
5 Write Subtraction Sentences
1. Identify the parts of a subtraction sentence
2. Write subtraction sentences to represent pictures

Module Key Words:

Key Words
Part
Whole
Subtract
Subtraction
Equation
Take away
Difference
Counting-back strategy
Doubles
Parts
Subtraction sentence

Module Assignments:

Lesson # Lesson Title Page # Assignment Title
1 Subtraction Properties 4 It’s Your Turn!
1 Subtraction Properties 5 Write It Out!
2 Count Back to Subtract 4 It’s Your Turn!
2 Count Back to Subtract 5 Write It Out!
3 Use Doubles to Subtract 5 It’s Your Turn!
4 Relate Addition and Subtraction 4 It’s Your Turn!
4 Relate Addition and Subtraction 5 Write it Out!
5 Write Subtraction Sentences 4 It’s Your Turn!
5 Write Subtraction Sentences 5 Write It Out!

Learning Coach Notes:

Lesson # Lesson Title Notes
1 Subtraction Properties In their Math notebook, have your student explain what the difference is in a subtraction problem.
2 Count Back to Subtract Ask your student to describe to you how to count back when subtracting.
3 Use Doubles to Subtract Ask your student to explain how they can use doubles to help them subtract.
4 Relate Addition and Subtraction In their Math Notebook, have your student explain what a fact family is and write down an example of a fact family.
5 Write Subtraction Sentences In their Math notebook, have your student write and label the parts of a subtraction sentence.

Module Guiding Questions:

When a student starts a lesson ask them questions to check for prior knowledge and understanding and to review concepts being taught. At the end of the lesson ask the questions again to see if their answer changes.

Lesson Title Question
Subtraction Properties
1. How can we subtract?
Count Back to Subtract
1. What subtraction strategies can we use in real life?
2. How can we count back to subtract?
Use Doubles to Subtract
1. What strategies can we use to subtract?
2. When can we use doubles to subtract?
Relate Addition and Subtraction
1. What is a part-part-whole chart?
2. How can we relate addition and subtraction?
Write Subtraction Sentences
1. How can we subtract to fit real-world situations?
2. How can we read a problem to help us write a subtraction sentence?

Module Video Questions:

When a student watches a video take time to ask them questions about what they watched. Suggested questions for the videos in this module are listed here. Suggestion: Have the student watch the entire video first all the way through. Then have them watch the video a second time, as they watch it pause the video and ask the questions.

Lesson Title Video Question
Use Doubles to Subtract Use Doubles to Subtract
1. Describe how you can use doubles to help you subtract.
Relate Addition and Subtraction Relate Addition and Subtraction
1. What are all equations made up of?
2. What is a fact family?
Write Subtraction Sentences Write Subtraction Sentences
1. What is included in a subtraction sentence?

Module Suggested Read Aloud Books:

Take time to read to your student or have them read aloud to you. Read a different book each day. While reading the book point out concepts being taught. You may purchase these books or find them at your local library. Suggested things to discuss while reading the book:

• What is the main idea?
• What are three things new you learned?
• How does this book relate to what you are learning about?

# Book Author Lexile Level

Module Outing:

Take some time to apply what your student is learning to the real world. Suggested outings are below.

# Outing