Chapter 12: Reasoning Strategies For Subtraction
Part 1: Counting Back
Part 2: Counting Up
Part 3: Using Ten
Part 4: Using Known Facts
Part 5: Flexible Use Of Strategies
This chapter formally introduces subtraction reasoning strategies. Practice using these strategies, not drill on fact answers, is very important because flexible and fluent use of these strategies will enable children to very quickly solve subtraction facts and provide ways of thinking that will enable them to solve problems with larger numbers. These strategies are key to helping children make progress with the mathematics curriculum in the middle grades.
1.OA.A Represent and solve problems involving addition and subtraction.
1.OA.B Understand and apply properties of operations and the relationship between addition and subtraction.
1.OA.C Add and subtract within 20.
1.OA.D Work with addition and subtraction equations.
1.NBT.A Extend the counting sequence.
1.NBT.B Understand place value.
1.NBT.C Use place value understanding and properties of operations to add and subtract.
2.OA.A Represent and solve problems involving addition and subtraction.
2.OA.B Understand place value.
2.OA.C Use place value understanding and properties of operations to add and subtract.