Subtraction Or Addition

Grade 1: Common Core Mathematics Standard

CCSS.MATH.CONTENT.1.OA.B.4
Understand subtraction as an unknown-addend problem. For example, subtract 10 - 8 by finding the number that makes 10 when added to 8.

Addition Versus Subtraction
I've seen many people struggle with the connection between addition and subtraction. Most people find addition to be easier and they prefer to use it whenever they can. They see subtraction as "scary". If you understand the relationship between addition and subtraction then you can use addition to make subtracting easier. 

Video

There's no need to be afraid of doing subtraction if you understand its relationship with addition. They are like best friends. They compliment each other. If you need to find the answer to a subtraction problem it is much easier to do so when you use addition to find the missing addend. 

You can even represent the numbers with dots or other pictures to get a better understanding of how to find the missing number. You're still thinking about the family and how many more dots you need to get to the total but having a visual may help you understand better. I personally like drawing out my numbers if they're small enough. 
Practice Problems

Problem 1: What is 15-3? What three numbers make up this "family" 15, 3, and __? Demonstrate how we would use addition to find the missing addend and explain how you did it. If you need help, look back at my video above. 

Problem 2: What is 7-2? What three numbers make up this family? Demonstrate how we would use addition to find the missing addend and explain how you did it. If you need help, refer to my video.

Questions to Consider...

• Is using addition helpful for you when solving subtraction problems?
• Does the use of dots make the problems easier for you?
• What other ways are there to make subtracting easier?

Other Sites and Games to Help you

https://www.youtube.com/watch?v=aK3FKEZJKec

https://mathgeekmama.com/fact-family-games/