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Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

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Page 1: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Second Grade CCSS–M, and Daily Math

Vacaville USDAugust 27, 2013

Page 2: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

AGENDA The CCSS-M: Math Practice Standards Daily Math Programs

Subitizing Ten Frames Number Bonds Place Value Computation And other areas

Addition and Subtraction Planning/Discussions

Page 3: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

The Common Core State Standards –

Mathematics

Page 4: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – M

The CCSS in Mathematics have two sections:Standards for Mathematical CONTENT

and Standards for Mathematical PRACTICE

The Standards for Mathematical Content are what students should know.

The Standards for Mathematical Practice are what students should do. Mathematical “Habits of Mind”

Page 5: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Standards for Mathematical Practice

Page 6: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS Mathematical Practices

OVE

RA

RC

HIN

G H

AB

ITS

OF

MIN

D1.

Mak

e se

nse

of p

robl

ems

and

pers

ever

e in

so

lving

them

6.At

tend

to p

recis

ion

REASONING AND EXPLAINING2. Reason abstractly and quantitatively3. Construct viable arguments and

critique the reasoning of others

MODELING AND USING TOOLS4. Model with mathematics5. Use appropriate tools strategically

SEEING STRUCTURE AND GENERALIZING7. Look for and make use of structure8. Look for and express regularity in

repeated reasoning

Page 7: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013
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Page 16: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013
Page 17: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Reflection

How are these practices similar to what you are already doing when you teach?

How are they different?

What concerns do you have with regards to the Standards for Mathematical Practice?

Page 18: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Standards for Mathematical Content

Page 19: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Standards for Mathematical Content

Are a balanced combination of procedure and understanding.

Stress conceptual understanding of key concepts and ideas

Page 20: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Standards for Mathematical Content

Continually return to organizing structures to structure ideas place value properties of operations

These supply the basis for procedures and algorithms for base 10 and lead into procedures for fractions and algebra

Page 21: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

“Understand”

means that students can… Explain the concept with mathematical

reasoning, including Concrete illustrations Mathematical representations Example applications

Page 22: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Organization K-8

Domains Larger groups of related standards.

Standards from different domains may be closely related.

Page 23: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Domains K-5

Counting and Cardinality (Kindergarten only)

Operations and Algebraic Thinking Number and Operations in Base Ten Number and Operations-Fractions

(Starts in 3rd Grade) Measurement and Data Geometry

Page 24: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Organization K-8

Clusters Groups of related standards. Standards

from different clusters may be closely related.

Standards Defines what students should understand

and be able to do. Numbered

Page 25: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013
Page 26: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

A Daily Math Program

Page 27: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

5 Big Ideas

1. From Kindergarten on, help children develop flexible ways of thinking about numbers by having them “break apart” numbers in multiple ways

Page 28: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

5 Big Ideas

2. From their earliest days in school, children should regularly solve addition, subtraction, multiplication, and division problems.

Page 29: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

5 Big Ideas

3. Problem solving of all types should be a central focus of instruction.

Page 30: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

5 Big Ideas

4. Develop number sense and computational strategies by building on children’s ideas and insights.

Page 31: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

5 Big Ideas

5. Teach place value and multi-digit computation throughout the year rather than as “chapters”.

Page 32: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Number Sense

What is “number sense”?

The ability to determine the number of objects in a small collection, to count, and to perform simple addition and subtraction, without instruction.

Page 33: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Visualize Numbers

I am going to show you a slide for a few seconds

Record the number of dots in Box A and in Box B

READY?

Page 34: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Box A Box B

Page 35: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Record your answers

Box A

Box B

Page 36: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Share

On a scale of 1-5, how confident are you that your answer is correct?

Page 37: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

SUBITIZING

Ability to recognize the number of objects in a collection, without counting

When the number exceeds this ability, counting becomes necessary

Page 38: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Box A Box B

Page 39: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Perceptual Subitizing

Maximum of 5 objects

Helps children Separate collections of objects into single

units Connect each unit with only one number

word Develops the process of counting

Page 40: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subitizing

Let’s try again.

Ready??

Page 41: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Box C Box D

Page 42: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Record your answers

Box C

Box D

Page 43: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Share

On a scale of 1-5, how confident are you that your answer is correct?

Page 44: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Box C Box D

Page 45: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Box C Box D

Page 46: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Conceptual Subitizing

Allows children to know the number of a collection by recognizing a familiar pattern or arrangement

Helps young children develop skills needed for counting

Helps develop sense of number and quantity

Page 47: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Children who cannot conceptually subitize will have problems learning basic arithmetic processes

Page 48: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Practicing Subitizing

Use cards or objects with dot patterns Groups should stand alone Simple forms like circles or squares Emphasize regular arrangements that

include symmetry as well as random arrangements

Have strong contrast with background

Avoid elaborate manipulatives

Page 49: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

How Many Dots?

Page 50: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

What’s 1 more than

Page 51: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

What’s 1 less than

Page 52: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Ten Frames and

Dot Patterns

Page 53: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Ten Frames

Page 54: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Ten Frames

Page 55: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Ten Frames

Page 56: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Base 10 Blocks

Page 57: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Base 10 Blocks

Page 58: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Base 10 Shorthand

Page 59: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Base 10 Shorthand

Page 60: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Tens Facts

7 + 3 = 10

Page 61: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Tens Facts

6 + 4 = 10

Page 62: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Tens Facts

8 + 2 = 10

Page 63: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Learning Progression

Concrete

Representational

Abstract

Page 64: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Part-Whole Relations

Page 65: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

4 4 4 4 4

Number Bonds

Page 66: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Number Bonds – 17

1717

17

17

1717

17

17

Page 67: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Number Bonds – 43

4343

43

43

4343

43

43

Page 68: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Number of the Day

Number of the Day of School Counting Counting back Place Value

Straws Base 10 Blocks Hundred’s Chart

Computation

Page 69: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Number of the Day

Today is the 9th day of school What is 1 more than 9? What is one less than 9? Find all the possible number bonds (using 2

numbers) that you can make with 9.

Page 70: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Number of the Day

Today is the 78th day of school Write 78 in expanded form. What is 1 more than 78? 1 less? What is 10 more than 78? 10 less? Find at least 3 number sentences for 78.

Use at least 3 numbersUse at least 2 different operations

Page 71: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Random Number of the Day

The number of the day is:

436 Who can read the number? What digit is in the ten’s place? The

hundred’s place? Write the number in expanded form. What is 1 more than 436? 1 less? What is 10 more than 436? 10 less? What is 100 more than 436? 100 less? Find at least 3 number sentences for 436.

Page 72: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Random Number of the Day II

Popsicle sticks What is the number? Write it in words. Where would it be located on the

number line? Hundred’s Tens

Counting Start at number and count by 1’s; 2’s; 5’s;

10’s

Page 73: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

My Number of the Day

Is my number larger or smaller than your number? How do you know? Fill the number in so that each makes a

true statement:___ < ___ and ___ > ___

Write a number that is larger than the number of the day.

Write a number that is smaller than the number of the day.

Page 74: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS - NBTUnderstand place value.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:

a. 100 can be thought of as a bundle of ten tens — called a “hundred.”

b. The numbers 100, 200, 300, 400, 500, 600, 700, 800, 900 refer to one, two, three, four, five, six, seven, eight, or nine hundreds (and 0 tens and 0 ones).

Page 75: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS - NBTUnderstand place value.2. Count within 1000; skip-count by 2s, 5s, 10s, and 100s. CA3. Read and write numbers to 1000 using base-ten numerals, number names, and expanded form.4. Compare two three-digit numbers based on meanings of the hundreds, tens, and ones digits, using >, =, and < symbols to record the results of comparisons.

Page 76: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – NBT

8. Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.

Page 77: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – MD

6. Represent whole numbers as lengths from 0 on a number line diagram with equally spaced points corresponding to the numbers 0, 1, 2, ..., and represent whole-number sums and differences within 100 on a number line diagram.

Page 78: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Math Talk

Students do better in classrooms where teachers use numbers as regular part of day

Page 79: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Reflection

Where, in the course of a normal day, can you find places to talk about numbers OUTSIDE OF MATH TIME?

Where do numbers occur in the everyday lives of your students?

Page 80: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Daily Math, continuedNumber of Day on Calendar Rote Counting Place Value with smaller numbers, i.e.,

10 and ______ more Calendar Questions – Days of the week,

months of the year, tomorrow and yesterday, how many Saturday’s have we had, looking at the columns of the calendar, etc.)

Page 81: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Daily Math, continuedNumber of Day on Calendar Addition Problems Number Bonds 1 more 1 less, 10 more 10 less Predicting

Page 82: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Daily Math, continuedWord Problems All four operations ( +, -, x, ÷) Clear action problems verses passive

problems All problem types appropriate to grade

level (see chart)

Page 83: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – OA

Represent and solve problems involving addition and subtraction.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.

Page 84: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Daily Math, continuedGeometry Plane Shapes: Triangles, Quadrilaterals,

Pentagons, Hexagons Solids: Cubes Be able to identify critical attributes Name shape based on critical attributes Continue to review shapes from K-1

Page 85: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – Geometry

1. Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces.5 Identify triangles, quadrilaterals, pentagons, hexagons, and cubes. Sizes are compared directly or visually, not compared by measuring.

Page 86: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Daily Math, continuedPatterns Predict the next element in the pattern

(shape, numeric, location, etc.) Identifying the repeating part

Page 87: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Daily Math, continuedGraphs and Data At least once a month – related to

things about the kids Graphs represent real people and real

data Ask a wide variety of problems related

to the graph including “What would happen if….” questions

Page 88: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – MD Represent and interpret data.9. Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.10. Draw a picture graph and a bar graph (with single-unit scale) to represent a data set with up to four categories. Solve simple put-together, take-apart, and compare problems using information presented in a bar graph.

Page 89: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Daily Math, continuedTime Morning, afternoon, evening, am, pm Order of events To the nearest 5 minutes (depends on

grade level)

Page 90: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Daily Math, continuedMoney Names of Coin Values of Coin Make 37 in at least 3 ways Write 84 cents in 2 different ways

Page 91: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – MD Work with time and money.7. Tell and write time from analog and digital clocks to the nearest five minutes, using a.m. and p.m. Know relationships of time (e.g., minutes in an hour, days in a month, weeks in a year). CA8. Solve word problems involving dollar bills, quarters, dimes, nickels, and pennies, using $ and ¢ symbols appropriately. Example: If you have 2 dimes and 3 pennies, how many cents do you have?

Page 92: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition and Subtraction

Page 93: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – M Add and subtract within 20.2. Fluently add and subtract within 20 using mental strategies.2 By end of Grade 2, know from memory all sums of two one-digit numbers.

2 See standard 1.OA.6 for a list of mental strategies.

Page 94: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – M Use place value understanding and properties of operations to add and subtract.5. Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.6. Add up to four two-digit numbers using strategies based on place value and properties of operations.

Page 95: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – M 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.

Page 96: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

CCSS – M 7.1 Use estimation strategies to make reasonable estimates in problem solving. CA9. Explain why addition and subtraction strategies work, using place value and the properties of operations. Explanations may be supported by drawings or objects.

Page 97: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Teaching for Understanding

Telling students a procedure for solving computation problems and having them practice repeatedly

rarely results in fluency

Because we rarely talk about how and why the procedure works.

Page 98: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Teaching for Understanding

Students do need to learn procedures for solving computation problems

But emphasis (at earliest possible age) should be on why they are performing certain procedure

Page 99: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Research

Students who learn rules before they learn concepts tend to score significantly lower than do students who learn concepts first

Initial rote learning of a concept can create interference to later meaningful learning

Page 100: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Gretchen – 1st Grade70 – 23

Page 101: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Progression

Concrete Pictorial or Visual or

Representational Abstract

Invented Algorithms Alternate Algorithms Traditional Algorithms

Page 102: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Invented Procedures

Allow students to invent and develop their own procedures based on what they already know

Page 103: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Fact Fluency Fact fluency must be based on

understanding operations and thinking strategies.

Students must Connect facts to those they know Use mathematics properties to make

associations Construct visual representations to develop

conceptual understanding.

Page 104: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Math Facts Direct modeling / Counting all Counting on / Counting back / Skip

Counting Invented algorithms

Composing / Decomposing Mental strategies

Automaticity

Page 105: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition

Page 106: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

3 + 2

Page 107: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

4 + 3

Page 108: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

4 + 3

Page 109: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Domino Facts

Page 110: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Domino Facts

Page 111: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Tens Facts

7 + 3 = 10

Page 112: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

7 + 5

Page 113: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

8 + 6

Page 114: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 7 + 5 Make ten

7 + 5

3 2

210 +

12

Page 115: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 8 + 6 Make ten

8 + 6

2 4

410 +

14

Page 116: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 28 + 6

Page 117: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 28 + 6 Make tens

28 + 6

2 4

430 +

34

Page 118: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 28 + 6

Page 119: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 28 + 6

8 ones + 6 ones = 14 ones 14 ones = 1 ten + 4 ones

28+ 6

1

4

2 tens + 1 ten = 3 tens

3

Page 120: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Adding 2-digit numbers

Miguel – 1st Grade30 + 16

Connor – 1st Grade39 + 25

How is the way these students solved the problems different from the way we typically teach addition?

Page 121: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition: 28 + 34

Page 122: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 28 + 34 Plan to make tens

28 + 34

2 32

3230 +

62

Page 123: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 46 + 38 Plan to make tens

46 + 38

4 34

3450 +

84

Page 124: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition: 28 + 34

Page 125: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition: 28 + 34

…adds tens and tens, ones and ones…

Page 126: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition: 28 + 34

… and sometimes it is necessary to compose a ten

Page 127: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition: 28 + 34

Page 128: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition: 28 + 34

Page 129: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

28 + 34

20 + 8 + 30 + 4

Addition – 28 + 34

50 12

= 62210

Page 130: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 46 + 38 Add Tens, Add Ones, and Combine

46 + 38

40 + 30 = 706 + 8 = 1470 + 14 = 84

This can also be done as add ones, add tens, and combine.

701484

Page 131: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 546 + 278

546 + 278

500 + 200 40 + 70 6 + 8

700110 14824

Page 132: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 546 + 278

Expanded Form

500 + 40 + 6 + 200 + 70 + 8

700 + 110 + 14 810 + 14

824

Page 133: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 46 + 38 Add Tens, Add On Ones

46 + 38Add tens 40 + 30 = 70

Add on ones 70 + 6 = 76

76 + 8 = 84

Be careful about run on equal signs!

Page 134: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 46 + 38 Add On Tens, Then Ones

46 + 38Add on tens 46 + 30 = 76

Add on ones 76 + 8 = 84

Be careful about run on equal signs!

Page 135: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 546 + 278

Add On Hundreds, Tens, and Ones546 + 278 = 546 + 200 = 746 + 70 = 816 + 8 =

746816824

Page 136: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition – 46 + 38 Compensate

46 + 38 Add a nice number 46 + 40 = 86

(Think: 38 is 2 less than 40)

Compensate 86 – 2 = 84

Page 137: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Addition

Try at least 2 different strategies on each problem1. 57 + 6 2. 48 + 37

3. 63 + 29 4. 254 + 378

5. 538 + 296

Page 138: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Vertical vs Horizontal Why do students need to be given

addition (and subtraction) problems both of these ways?

279 + 54 = 279+ 54

Page 139: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction

Page 140: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

1. Katie had 5 candy hearts. She gave 2 of them to Nick. How many hearts does Kate have left for herself?

2. Katie has 5 candy hearts. Nick has 2 candy hearts. How many more does Katie have?

Page 141: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

5 – 2

Page 142: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

5 – 2

Page 143: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

0 1 2 3 4 5 6 7 8 9 10 11

12

5 – 2

Page 144: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

0 1 2 3 4 5 6 7 8 9 10 11

12

5 – 2

Page 145: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction

How do you currently teach subtraction? “Take-away” “The distance from one number to the

other”

Additional Strategies

Page 146: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 13 – 6 Decompose with tens

13 – 6 =

13 – 3 = 10

10 – 3 = 7

3 3

Page 147: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 15 – 7 Decompose with tens

15 – 7 =

15 – 5 = 10

10 – 2 = 8

5 2

Page 148: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Developing Subtraction

Connor – 1st Grade25 – 8

Connor – 1st Grade70 – 23

Page 149: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 43 – 6 Take Away Tens, Then Ones

43 – 6 =

43 – 3 = 40

40 – 3 = 37

33

Page 150: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 73 – 46 Take Away Tens, Then Ones

73 – 46 =

73 – 40 = 33

33 – 6 = 27

40 6

Page 151: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 73 – 46 Take Away Tens, Then Ones

73 – 46 =

73 – 40 = 33

33 – 3 = 30

30 – 3 = 27

40 633

Page 152: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 53 – 38

Page 153: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 53 – 38

Page 154: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 53 – 38

Page 155: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 53 – 38

Page 156: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 53 – 38

Page 157: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 53 – 38

Page 158: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 53 – 38

Page 159: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 73 – 46 Regrouping and Ten Facts

73

– 46

6

72

60 – 40 = 20

Page 160: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 42 – 29 Regrouping and Ten Facts

42

– 29

3

31

10 + 2- 9

30 – 20 = 10

1

Page 161: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 57 – 34 57 34

(50 + 7) (30 + 4)

20 3+ = 23

Do I have enough to be able to subtract?

Page 162: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 52 – 34

52 34 (50 + 2) (30 + 4)

(40 + 12) (30 + 4)

10 8+ = 18

Do I have enough to be able to subtract?

Page 163: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction 300 – 87 Constant Differences

0 87 300

Suppose I slide the line down 1 space?

299

86

299 – 86 =

Page 164: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 73 – 46 Constant Differences

73

– 4627

+ 4

+ 4 = 77

= 50

Page 165: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction: 73 – 46 Regrouping by Adding Ten

73

– 46

13

5

27

Page 166: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction – Adding On

471 – 285 Start at 285 Add 5 Now at 290 Add 10 (15) Now at 300 Add 100 (115) Now at 400 Add 70 (185) Now at 470 Add 1 (186) Now at 471 – DONE!

Page 167: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction

Try at least 2 different strategies on each problem

1. 53 – 7 2. 58 – 36

3. 73 – 29 4. 554 – 327

5. 538 – 298

Page 168: Second Grade CCSS–M, and Daily Math Vacaville USD August 27, 2013

Subtraction

Planning your strategy Not all problems are created equal! What strategy would be the most

effective.

NOT “one size fits all”