In this lesson, we will review some of the math strategies that can be used for addition and subtraction.
Add 1, 2, 3 to 1-digit number
This video explains the addition strategy for adding 1, 2, and 3 to any number by counting on.
In this video, you will learn about addition properties including the commutative property of addition, the zero property of addition, and the associative property of addition.
Addition Doubles Rock
Doubles and Near Doubles
Addition Strategy (Doubles)
Mental Math Strategies: Make 10
This video shows how to use mental strategies to add within 20 using the "make 10" strategy. This is one of the strategies suggested in the Common Core State Standards for Mathematics, 1.OA.6 and 2.OA.2.
With practice, this strategy can help students gain fluency when adding within 20. Eventually students will memorize these facts, which is expected by the end of grade 2.
Make 10 Strategy for Addition
Step 1: The first addend and what make ten?
Step 2: Write the number below the second addend?
Step 3: The number below the second addend and what make the scond addend?
Step 4: Add the rest to 10
Mental Math Strategies: Break Down to 10
This video explains how to use mental strategies to subtract within 20 using the "break down to 10" strategy.
Mental Math Strategies: Addition & Subtraction Relationship
This video explains how to use mental strategies to add and subtract within 20 using the relationship between addition and subtraction.
Mental Math Strategies: Use Known Equivalent Sums This video explains how to use mental strategies to add within 20 using known sums to solve unknown sums.
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