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2 nd Grade Subtract within 1000 using concrete models.

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1 2 nd Grade Subtract within 1000 using concrete models

2 2.NBT.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....

3 Possible Objectives  Add within 1000 using concrete models.  Add within 1000 using drawings.  Add within 1000 using strategies based on place value.  Add within 1000 using properties of operations.  Add within 1000 using the relationship between addition and subtraction.  Subtract within 1000 using concrete models.  Subtract within 1000 using drawings.  Subtract within 1000 using strategies based on place value.  Subtract within 1000 using properties of operations.  Subtract within 1000 using the relationship between addition and subtraction.

4  Today we will subtract within 1000 using concrete models.

5 23 + 35 48 + 25 12 + 26 32 +19 Today we will subtract within 1000 using concrete models.

6 Concrete models-the hands on manipulatives that we use to build conceptual understanding of the mathematics. Within 1000-values up to 999 (hundreds place value) Today we will subtract within 1000 using concrete models.

7 234 - 121 Today we will subtract within 1000 using concrete models. Steps: 1.Read the problem. 2.Build the first value (and draw the representation). 3.Subtract the second value. 4.Record the symbolic representation.

8 235 - 124 346 - 236 555 - 111 486 - 213 Today we will subtract within 1000 using concrete models. Steps: 1.Read the problem. 2.Build the first value (and draw the representation). 3.Subtract the second value. 4.Record the symbolic representation.

9 Build-Write with exchanging/decomposing Build-Draw-Write with exchanging/decomposing Place Value Strategies Properties of Operations

10 Use addition to find the total number of objects arranged in an array

11 2.OA.4 Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.

12  Use addition to find the total number of objects arranged in an array.  Write an addition equation using arrays.

13  Today we will use addition to find the total number of objects arranged in an array.

14 4 + 4 5+ 5 + 5 + 5 3 + 3 2 + 2 + 2 Today we will use addition to find the total number of objects arranged in an array.

15 Array-an arrangement of objects in rows and columns. Today we will use addition to find the total number of objects arranged in an array. rows columns

16 Array-an arrangement of objects in rows and columns. Today we will use addition to find the total number of objects arranged in an array. Example: X X X Non-example: X

17 Steps: 1.Look at the array. 2.Determine the number of objects in one column. (This is the number of groups) 3.Determine the number of objects in one row. (This is the size of each group) 4.Write the equation. Today we will use addition to find the total number of objects arranged in an array. X X X

18 Today we will use addition to find the total number of objects arranged in an array. Steps: 1.Look at the array. 2.Determine the number of objects in one column. (This is the number of groups) 3.Determine the number of objects in one row. (This is the size of each group) 4.Write the equation. X X X

19 Today we will use addition to find the total number of objects arranged in an array. Steps: 1.Look at the array. 2.Determine the number of objects in one column. (This is the number of groups) 3.Determine the number of objects in one row. (This is the size of each group) 4.Write the equation. X X

20 Today we will use addition to find the total number of objects arranged in an array. Steps: 1.Look at the array. 2.Determine the number of objects in one column. (This is the number of groups) 3.Determine the number of objects in one row. (This is the size of each group) 4.Write the equation. X

21 Today we will use addition to find the total number of objects arranged in an array. Steps: 1.Look at the array. 2.Determine the number of objects in one column. (This is the number of groups) 3.Determine the number of objects in one row. (This is the size of each group) 4.Write the equation. X X X X X

22 partition rectangles into four equal shares

23 2.G.3 Partition circles and rectangles into two, three, or four equal shares, describe the shares using the words halves, thirds, half of, a third of, etc., and describe the whole as two halves, three thirds, four fourths. Recognize that equal shares of identical wholes need not have the same shape.

24 Possible Objectives  Partition circles into two equal shares.  Partition rectangles into two equal shares.  Partition circles into three equal shares.  Partition rectangles into three equal shares.  Partition circles into four equal shares.  Partition rectangles into four equal shares.

25  Today we will partition rectangles into four equal shares.

26 Today we will partition rectangles into four equal shares.

27 Partition-to portion or separate into parts Equal Shares-parts that are the same size Today we will partition rectangles into four equal shares.

28 Steps: 1.Determine how many equal parts you need. 2.Partition the shape by drawing the line(s). 3.Explain what each part is called. Today we will partition rectangles into four equal shares.

29 Steps: 1.Determine how many equal parts you need. 2.Partition the shape by drawing the line(s). 3.Explain what each part is called. “It is important for students to understand that fractional parts may not be symmetrical. The only criteria for equivalent fractions is that the area is equal… It is important for students to see circles and rectangles partitioned in multiple ways so they learn to recognize that equal shares can be different shapes within the same whole.” North Carolina Department of Public Instruction 2 rd Grade Unpacked Content p. 33


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