Lesson 3-3
Thinking Addition to
10 to Subtract
Mr. Baker
2nd Grade
Today We Will Learn!
• The inverse relationship
between addition and
subtraction can be used to
find subtraction facts; every
subtraction fact has a
related addition fact.
Vocabulary Review
The Purpose!!
You have learned strategies to
help you subtract, such as
using doubles facts.
Today, you will learn to use
related addition facts to help
you subtract.
Connect!!!!
(have 8 students come to the front of the class)
• How many students are there?
• I want to know how many sat down.
8 – 5 = _____
• I can use addition to find the missing
number.
• What do we need to add to 5 to get 8?
• If 5 + 3 is 8, then 8 minus 5 is 3.
• So three children sat down.
(have 3 sit down)
The Problem!!
(put 7 counters in a row with yellow/white side up. Turn 3 counters red.)
•What addition sentence do the counters
model?
7 – 4 = _____
How can knowing 3 + 4 = 7 help you solve
7 – 4 = ____?
Let’s Explore!! (page 79)
•Let’s record our problem on page 79.
•Let’s practice some more.
2. Show me 5 + 3 = with your counters.
Record your answer on your work mat.
Now write a related subtraction fact.
3. Show me 1 + 5 = with your counters.
Record your answer on your work mat.
Now write a related subtraction fact.
4. Show me 2 + 7 = with your counters.
Record your answer on your work mat.
Now write a related subtraction fact.
Let’s Explore!! (page 79)
Learning Bridge!
• In this lesson, You will learn how to use
addition facts to help you subtract.
• Let’s watch and learn!
– CLICK HERE
–
(After learning bridge use guided practice page to continue lesson.)
Close
• In this lesson, your learned that you can
use an addition fact to solve a related
subtraction fact!
• GREAT JOB!
Math Journal & Technology
• On your I Pad go to the math folder and begin
working on Cloud Math or Math Plus Edge.