Chapter 4
Addition & Subtraction within 1,000
2nd Grade: Chapter 4 Outline
Week 8 - Week 11
Essential Questions:
- How does understanding place value help you solve three digit addition and subtraction?
- How can I apply my understanding of place value to solve addition and subtraction story problems?
- How does my basic knowledge of facts help me solve a multi-digit addition problem?
Content:
Students will know and understand:
- Concept of Addition
- Concept of Subtraction
- Concept of Regrouping
- Picture Representations
Skills:
Students Will:
- Solve addition word problems with and without regrouping.
- Solve subtraction word problems with and without regrouping.
- Draw and use picture models so solve one and 2-step problems with addition and subtraction.
- Fluently add and subtract within 20 using mental strategies.
Upon completion of Unit 4:
2.OA.A.1. Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.
2.OA.B.2. Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers.
2.NBT.A.1. Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones. Understand the following as special cases:
2.NBT.B.5. Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
2.NBT.B.6. Add up to four two-digit numbers using strategies based on place value and properties of operations.
2.NBT.B.7. Add and subtract within 1000, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, ones and ones; and sometimes it is necessary to compose or decompose tens or hundreds.
2.NBT.B.8. Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.
2.NBT.B.9. Explain why addition and subtraction strategies work, using place value and the properties of operations.
2.MD.B.5. Use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units, e.g., by using drawings (such as drawings of rulers) and equations with a symbol for the unknown number to represent the problem.