Parent Support for K-5 Math

First Grade Mathematics

Unit 2: Addition and Subtraction Fact Strategies

What will your child learn in Unit 2?

In Unit 2, first graders will learn basic fact math strategies for addition and subtraction. Addition and subtraction math fact strategies are mental math techniques that provide a bridge from understanding the meaning of addition and subtraction to quickly and accurately recalling addition and subtraction facts. Children go through phases to quickly and accurately recall basic math facts. Children go through phases to quickly and accurately recall basic math facts. See chart below for description of strategies. Unit 2 will primarily focus on counting and reasoning strategies.

Furthermore, first graders will learn how to organize data into categories and how to interpret data. They will create real, picture, and bar graphs. They will use the graphs to ask and answer questions.

What math strategies will your child use in Unit 2?

There are a variety of strategies to help solve basic facts. The type of strategy depends on the kind of basic fact problem. The handout below gives an explanation of the different types of basic fact math strategies.

Check out the videos below to see the math strategies in action.

Most of the explanations are from students from our district. Thank you to the students for volunteering to explain their thinking!

• Near-Doubles (Example 1)
• Near-Doubles (Example 2)
• Make Ten (Example 1)
• Make Ten (Example 2)
• Subtraction as Think Addition (Example 1)
• Subtraction as Think Addition (Example 2)

How can you support your child at home to reinforce the concepts taught in Unit 2?

There are several ways to have your child practice the math concepts at home. Try the following activities:

• Give your child an addition or subtraction basic fact problem and have them solve it mentally and explain their thinking verbally.
• Give your child a flashcard that contains a subtraction problem. Have your child find an addition flashcard that can be used to solve the subtraction problem.
• Give your child a near-double flashcard (Ex. 6 + 7). Have your child find a doubles flashcard that can be used to solve the near-double problem (Ex. 6 + 6 or 7+7).
• Do a 5-minute drill using selected flashcards that contain related facts. For example, only flash problems that are near-doubles for 5 minutes.
• Play Salute.
• Have your child create a story problem that involves addition or subtraction to solve the problem. Challenge him or her to create different types of story problems.
• Visit the online rekenrek (number rack) to help your child explore and discover a variety of addition and subtraction strategies. Click the “i” on the bottom of the website for instructions on how to use it.
• Visit How Many Under the Shell? to help your child practice addition and subtraction.
• Visit Cross the Swamp to help your child practice addition and subtraction equations. Your child will pick a missing operation (+ or -) and a number to complete the equation.
• Visit Deep Sea Duel to practice picking addends with a specified sum.
• Visit Let’s Learn those Facts to help your child master addition facts.
• Math Games for Home: Print the handouts to practice concepts through games.