Module 15: Two-Digit Mental Math Subtraction Strategies- Math 2A - Course Guide

Module Overview:

In this module, students will use fact families to subtract numbers, use mental math to solve two-digit subtraction and take apart numbers to subtract two-digit numbers. They will use the take-apart strategy to subtract two-digit numbers mentally and use the make-ten strategy to subtract two-digit numbers.

Module Materials:

Lesson #	Lesson Title	Material(s)
1	Two-Digit Fact Families	crayons or colored pencils pen or pencil scissors
2	Mentally Subtract Two-Digit Numbers	crayons or colored pencils pen or pencil
3	Take Apart Tens to Subtract	crayons or colored pencils pen or pencil scissors
4	Apply the Take-Apart Strategy	crayons or colored pencils pen or pencil
5	Make Ten to Subtract	stacking blocks crayons or colored pencils pen or pencil

Module Objectives:

Lesson #	Lesson Title	Objective(s)
1	Two-Digit Fact Families	Use fact families to subtract numbers
2	Mentally Subtract Two-Digit Numbers	Use mental math to solve two-digit subtraction
3	Take Apart Tens to Subtract	Take apart numbers to subtract two-digit numbers.
4	Apply the Take-Apart Strategy	Use the take-apart strategy to subtract two-digit numbers mentally
5	Make Ten to Subtract	Use the make-ten strategy to subtract two-digit numbers

Module Key Words:

Key Words
Fact family Fact-family triangle Whole ten Mental math Non-whole ten Take apart Friendly numbers

Module Assignments:

Lesson #	Lesson Title	Page #	Assignment Title
1	Two-Digit Fact Families	4	Hands-On
2	Mentally Subtract Two-Digit Numbers	4	Hands-On
3	Take Apart Tens to Subtract	4	Hands-On
4	Apply the Take-Apart Strategy	4	Hands-On
5	Make Ten to Subtract	4	Hands-On

Learning Coach Notes:

None

Guiding Questions

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
Two-Digit Fact Families	How can you use fact families to subtract?
Mentally Subtract Two-Digit Numbers	Can you mentally subtract whole tens?
Take Apart Tens to Subtract	What is the Take Apart Strategy for subtraction?
Apply the Take-Apart Strategy	How can I apply the take-apart strategy when subtracting two-digit numbers?
Make Ten to Subtract	What is the make-ten subtraction strategy?

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

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