1 of 24

Second Grade Math

The First Nine Weeks

2 of 24

Overview of First Nine Weeks

  • Solve Addition and Subtraction Problems up to 20

  • Use Attributes to Classify 2-D Shapes and 3-D Solids and Review Time

  • Use Non-Standard Algorithm to Solve One-Step Problems with up to Two 2-Digit Numbers

3 of 24

Classify and sort polygons with 12 or fewer sides according to attributes, including identifying the number of sides and number of vertices

  • Vertex - 1 corner
  • Vertices - 2 or more corners
  • Regular and irregular

4 of 24

Create two-dimensional shapes based on given attributes, including number of sides and vertices

  • Specify the number of sides and/or vertices

  • They can draw shapes:
    • With markers, crayons, pencils, etc.
    • With a cookie sheet that has a thin layer of sand, salt, shaving cream, etc.

  • They can create shapes:
    • With spaghetti noodles, play-doh, cutting paper, etc.

5 of 24

Classify and sort three-dimensional solids, including spheres, cones, cylinders, rectangular prisms (including cubes as special rectangular prisms), and triangular prisms, based on attributes using formal geometric language

  • Vertices (More than 1 corner)

  • Vertex (One corner)

  • Face (Flat surface with straight edges)

  • Edge (Where 2 faces touch)

6 of 24

Classify and sort three-dimensional solids, including spheres, cones, cylinders, rectangular prisms (including cubes as special rectangular prisms), and triangular prisms, based on attributes using formal geometric language

7 of 24

Compose two-dimensional shapes and three-dimensional solids with given properties of attributes

  • “Make a solid figure with 8 vertices, 6 equal faces, and 12 edges.”
  • “Make a shape with 8 vertices and 8 sides.”
  • Can use straws and play-doh or mini-marshmallows and spaghetti noodles
  • Can draw the 2-D shapes

8 of 24

Decompose two-dimensional shapes such as cutting out a square from a rectangle, dividing a shape in half, or partitioning a rectangle into identical triangles and identify the resulting geometric parts

  • Parent can draw the shape to be divided and give the student a pencil or spaghetti noodle to divide the shape.

9 of 24

Read and write time to the nearest hour and half-hour using analog and digital clocks and distinguish between a.m. and p.m.

  • Reading and Writing time to the nearest hour and half-hour is a review from first grade
  • Distinguishing between a.m. and p.m. is new for second grade
    • “Billy eats dinner at 6 o’clock. Would it be reasonable to eat dinner at 6 a.m. or 6 p.m.?”
    • “Carol starts walking to school at 7:15. Would it be reasonable to walk to school at 7:15 a.m. or 7:15 p.m.?”

10 of 24

Recall basic facts to add and subtract within 20 with automaticity

  • Should have these memorized by the end of second grade
  • Work on them in strategy groups
    • +/- 0
    • +/- 1
    • +/- 2
    • Doubles
    • Combinations that make 10

11 of 24

Use Combinations that Make 10 to Create Combinations that Make 20

  • If I know that 4 and 6 make 10, then I know that 14 and 6 make 20.

  • If I know that 5 and 5 make 10, then I know that 15 and 5 make 20.

  • Then…..we can extend…..

  • If I know that 7 and 3 make 10, then I know that 47 and 3 make 50.

12 of 24

Count by Tens off the Decade Numbers

  • 33, 43, 53, 63, 73, 83, 93, 103

  • 46, 56, 66, 76, 86, 96, 106, 116

  • And backwards

  • 91, 81, 71, 61, 51, 41, 31

  • 175, 165, 155, 145, 135, 125

13 of 24

Locate the position of a given whole number on an open number line

  • Open Number Lines have few or no numbers
  • Develops number sense

14 of 24

Determine whether a number up to 40 is even or odd using pairings of objects to represent the number

  • NOT about memorizing 0, 2, 4, 6, 8 are even and that 1, 3, 5, 7, 9 are odd
  • About understanding why a number is even or odd

  • 10 is even

  • 9 is odd

15 of 24

Generate a number that is greater than or less than a given whole number up to 120 (1,200).

  • Start with numbers up to 120. Build up gradually

  • “Tell me a number that is greater than 52.”

  • “Tell me a number that is less than 88.”

16 of 24

Add up to two two-digit numbers and subtract two-digit numbers using mental strategies and algorithms based on knowledge of place value and properties of operations

Solve one-step word problems involving addition and subtraction within 20 (100) using a variety of strategies based on place value, including algorithms

17 of 24

Generate and solve problems situations for a given mathematical number sentence involving addition and subtraction of whole numbers within 20 (100)

Represent and solve addition and subtraction word problems where unknowns may be any one of the terms in the problem

18 of 24

Non-Standard Algorithms

  • Develops number sense
  • Preserves place value understandings
  • More than one correct way to approach a problem
  • Let student choose the way that makes sense to him or her
  • Problems should be solved mentally and then notated

19 of 24

Non-Standard Algorithms

  • 37 + 7
    • 7 can be split into 3 and 4
    • 37 and 3 are 40
    • 40 and 4 are 44
    • OR
    • 37 can be split into 30 and 7
    • 7 can be split into 3 and 4
    • 3 and 7 are 10
    • 10 and 30 are 40
    • 40 and 4 are 44

20 of 24

Non-Standard Algorithms

  • 36 + 28
    • 36 can be split into 30 and 6
    • 28 can be split into 20 and 8
    • 20 and 30 make 50
    • 6 can be split into 2 and 4
    • 8 and 2 make 10
    • 10 and 50 make 60
    • 60 and 4 make 64
    • OR
    • 36 and 20 make 56
    • 8 can be split into 4 and 4
    • 56 and 4 make 60
    • 60 and 4 make 64

21 of 24

Non-Standard Algorithms

  • 69 and 18
    • 69 is one away from 70
    • 18 can be split into 10 and 8
    • 70 and 10 make 80
    • 80 and 8 make 88
    • Take away the one that I added to make 70 from 88 and I have 87

22 of 24

Non-Standard Algorithms

  • 58 - 26
    • 58 minus 20 is 38
    • 38 minus 6 is 32

23 of 24

Non-Standard Algorithms

  • 35 - 18
    • 35 minus 10 is 25
    • 8 can be split into 5 and 3
    • 25 minus 5 is 20
    • 20 minus 3 is 17

24 of 24

Some Useful Websites

  • http://csisdmath.weebly.com/

  • In “Word Problems,” you will

find “Thinking Blocks” which is a

fabulous site!