Mathematics Common Core State Standards - PowerPoint PPT Presentation

1 / 135
About This Presentation
Title:

Mathematics Common Core State Standards

Description:

Mathematics Common Core State Standards ... – PowerPoint PPT presentation

Number of Views:358
Avg rating:3.0/5.0
Slides: 136
Provided by: PhilD68
Category:

less

Transcript and Presenter's Notes

Title: Mathematics Common Core State Standards


1
MathematicsCommon Core State Standards
2
(No Transcript)
3
The user has control
  • Sometimes a tool is just right for the wrong use.

4
Old Boxes
  • People are the next step
  • If people just swap out the old standards and put
    the new CCSS in the old boxes
  • into old systems and procedures
  • into the old relationships
  • Into old instructional materials formats
  • Into old assessment tools,
  • Then nothing will change, and perhaps nothing
    will

5
Standards are a platform for instructional systems
  • This is a new platform for better instructional
    systems and better ways of managing instruction
  • Builds on achievements of last 2 decades
  • Builds on lessons learned in last 2 decades
  • Lessons about time and teachers

6
Grain size is a major issue
  • Mathematics is simplest at the right grain size.
  • Strands are too big, vague e.g. number
  • Lessons are too small too many small pieces
    scattered over the floor, what if some are
    missing or broken?
  • Units or chapters are about the right size (8-12
    per year)
  • Districts
  • STOP managing lessons,
  • START managing units

7
What mathematics do we want students to walk away
with from this chapter?
  • Content Focus of professional learning
    communities should be at the chapter level
  • When working with standards, focus on clusters.
    Standards are ingredients of clusters. Coherence
    exists at the cluster level across grades
  • Each lesson within a chapter or unit has the same
    objectives.the chapter objectives

8
Lesson study and chapter planning
  • Lesson study may be more than wonderful, it may
    be necessary
  • We have to learn more about the way students
    think about specific mathematics in specific well
    designed problems
  • We have to learn how to get student thinking out
    into the open where we can engage it

9
Social Justice
  • Main motive for standards
  • Get good curriculum to all students
  • Start each unit with the variety of thinking and
    knowledge students bring to it
  • Close each unit with on-grade learning in the
    cluster of standards

10
Why do students have to do math problems?
  • to get answers because Homeland Security needs
    them, pronto
  • I had to, why shouldnt they?
  • so they will listen in class
  • to learn mathematics

11
Why give students problems to solve?
  • To learn mathematics.
  • Answers are part of the process, they are not the
    product.
  • The product is the students mathematical
    knowledge and know-how.
  • The correctness of answers is also part of the
    process. Yes, an important part.

12
Wrong Answers
  • Are part of the process, too
  • What was the student thinking?
  • Was it an error of haste or a stubborn
    misconception?

13
Three Responses to a Math Problem
  1. Answer getting
  2. Making sense of the problem situation
  3. Making sense of the mathematics you can learn
    from working on the problem

14
Answers are a black holehard to escape the pull
  • Answer getting short circuits mathematics, making
    mathematical sense
  • Very habituated in US teachers versus Japanese
    teachers
  • Devised methods for slowing down, postponing
    answer getting

15
Answer getting vs. learning mathematics
  • USA
  • How can I teach my kids to get the answer to this
    problem?
  • Use mathematics they already know. Easy,
    reliable, works with bottom half, good for
    classroom management.
  • Japanese
  • How can I use this problem to teach the
    mathematics of this unit?

16
Butterfly method
17
(No Transcript)
18
Use butterflies on this TIMSS item
  • 1/2 1/3 1/4

19
Set up
  • Not
  • set up a proportion and cross multiply
  • But
  • Set up an equation and solve
  • Prepare for algebra, not just next weeks quiz.

20
Foil FOIL
  • Use the distributive property
  • It works for trinomials and polynomials in
    general
  • What is a polynomial?
  • Sum of products product of sums
  • This IS the distributive property when a is a
    sum

21
Canceling
  • x5/x2 xx xxx / xx
  • x5/x5 xx xxx / xx xxx

22
Standards are a peculiar genre
  • 1. We write as though students have learned
    approximately 100 of what is in preceding
    standards. This is never even approximately true
    anywhere in the world.
  • 2. Variety among students in what they bring to
    each days lesson is the condition of teaching,
    not a breakdown in the system. We need to teach
    accordingly.
  • 3. Tools for teachersinstructional and
    assessmentshould help them manage the variety

23
Differences among students
  • The first response, in the classroom make
    different ways of thinking students bring to the
    lesson visible to all
  • Use 3 or 4 different ways of thinking that
    students bring as starting points for paths to
    grade level mathematics target
  • All students travel all paths robust, clarifying

24
Social Justice
  • Main motive for standards
  • Get good curriculum to all students
  • Start each unit with the variety of thinking and
    knowledge students bring to it
  • Close each unit with on-grade learning in the
    cluster of standards

25
(No Transcript)
26
Mathematical Practices Standards
  • Make sense of complex problems and persevere in
    solving them.
  • Reason abstractly and quantitatively
  • Construct viable arguments and critique the
    reasoning of others.
  • 4. Model with mathematics.
  • 5. Use appropriate tools strategically.
  • Attend to precision
  • Look for and make use of structure
  • 8. Look for and express regularity in repeated
    reasoning.
  • College and Career Readiness Standards for
    Mathematics

27
  • What key messages to communicate with principals?
  • Why elementary science and middle school math?
  • How will this work connect to other initiatives
    and efforts?
  • How will principal professional learning and
    support be organized?
  • What is the plan for REXO support collaboration
    next year?

28
Expertise and Character
  • Development of expertise from novice to
    apprentice to expert
  • Schoolwide enterprise school leadership
  • Department wide enterprise department taking
    responsibility
  • The Content of their mathematical Character
  • Develop character

29
Two major design principles, based on evidence
  • Focus
  • Coherence

30
The Importance of Focus
  • TIMSS and other international comparisons suggest
    that the U.S. curriculum is a mile wide and an
    inch deep.
  • On average, the U.S. curriculum omits only 17
    percent of the TIMSS grade 4 topics compared with
    an average omission rate of 40 percent for the 11
    comparison countries. The United States covers
    all but 2 percent of the TIMSS topics through
    grade 8 compared with a 25 percent non coverage
    rate in the other countries. High-scoring Hong
    Kongs curriculum omits 48 percent of the TIMSS
    items through grade 4, and 18 percent through
    grade 8. Less topic coverage can be associated
    with higher scores on those topics covered
    because students have more time to master the
    content that is taught.
  • Ginsburg et al., 2005

31
U.S. standards organization
  • Grade 1
  • Number and Operations
  • Measurement and Geometry
  • Algebra and Functions
  • Statistics and Probability

32
U.S. standards organization
  • 12
  • Number and Operations
  • Measurement and Geometry
  • Algebra and Functions
  • Statistics and Probability

33
(No Transcript)
34
Draw a line to represent a 30 inch race course.
Show where all four snails are when the first one
crosses the finish line.
  • Snail A
  • 5 inches in 10 minutes
  • Snail B 3 inches in 20 minutes
  • Snail C 1 inch in 15 minutes
  • Snail D 6 inches in 30 minutes

35
Making Sense of Tom, Dick and Harry
  • Suppose that it takes Tom and Dick 2 hours to do
    a certain job, it takes Tom and Harry 3 hours to
    do the same job and it takes Dick and Harry 4
    hours to do the same job.
  • 1.How long would it take Tom, Dick and Harry to
    do the same job if all 3 men worked together?
  • 2.Prepare an explanation on how to make sense of
    this problem. You will explain to elem. Teachers.

36
Angel ran 30 laps around the gym in 15 minutes.
(A lap is once around the track.)
  • After her run Angel made this calculation
  • 30 15 2
  • What does the 2 tell you about Angels run?
  • How do you know that is what it tells you?

37
Assessment
  • I. assessment and motivation
  • II. what students produce to be assessed

38
Angel ran 30 laps around the gym in 15 minutes.
(A lap is once around the track.)
  • Her coach made this calculation
  • 15 30 0.5
  • c. What does the 0.5 tell you about Angels
    run?
  • d. How do you know that is what it tells you?

39
1. Patti runs a 2.5 miles in 30 minutes.
  • Make a table and a double number line for Pattis
    running show at least 5 times.
  • How far did Patti run (distance, d) in 5 minutes?
  • Write a formula to calculate Pattis distance (d)
    for any time (t)?
  • d. How long did it take (time, t) Patti to run 2
    miles?
  • e. Write a formula to calculate Pattis time (t)
    for any distance (d)?

40
Her dog, Boe, runs twice as fast as Patti.
  • Represent his data in a table or double number
    line
  •   Write a formula to calculate Boes distance (d)
    for any time (t)?
  • c. Write a formula to calculate Boes time (t)
    for any distance (d)?

41
How would you calculate the rate, r, in miles, d,
per minute, t?
  • Write formulas using r, d, and t that show
  • Pattis rate
  • Boes rate
  • The rate is the speed

42
Make up problems
  • Here are three quantities 4 pounds, 5, 1.25
    per pound
  • Make up a problem that uses two of these
    quantities as givens and has the third as the
    answer.
  • Make up another problem switching around the
    givens and the answer.
  • Make up a third problem switching givens and
    answer.

43
K-5 quantities and number line
  • Compare quantities, especially length
  • Compare by measuring units
  • Add and subtract with ruler
  • Diagram of a ruler
  • Diagram of a number line
  • Arithmetic on the number line based on units
  • Representing time, money and other quantities
    with number lines

44
Number line
  • Ruler and number line concepts that are often
    underdeveloped. In elementary grades
  • A number is a pointa location
  • and also a length from 0. (like order and
    cardinality)
  • Lengths between whole numbers are equal
  • The length from 0 to 1 is the unit length
  • Any length can be partitioned into any number of
    equal length parts

45
Fractions Progression
  • Understanding the arithmetic of fractions draws
    upon four prior progressions that informed the
    CCSS
  • equal partitioning,
  • unitizing,
  • number line,
  • and operations.

46
Units are things you count
  • Objects
  • Groups of objects
  • 1
  • 10
  • 100
  • ¼ unit fractions
  • Numbers represented as expressions

47
Units add up
  • 3 pennies 5 pennies 8 pennies
  • 3 ones 5 ones 8 ones
  • 3 tens 5 tens 8 tens
  • 3 inches 5 inches 8 inches
  • 3 ¼ inches 5 ¼ inches 8 ¼ inches
  • ¾ 5/4 8/4
  • 3(x 1) 5(x1) 8(x1)

48
Unitizing links fractions to whole number
arithmetic
  • Students expertise in whole number arithmetic is
    the most reliable expertise they have in
    mathematics
  • It makes sense to students
  • If we can connect difficult topics like fractions
    and algebraic expressions to whole number
    arithmetic, these difficult topics can have a
    solid foundation for students

49
Grade 3unit fractions
  • The length from 0 to1 can be partitioned into 4
    equal parts. The size of the part is ¼.
  • Unit fractions like ¼ are numbers on the number
    line.

50
Adding and multiplying Unit Fractions
  • Whatever can be counted can be added, and from
    there knowledge and expertise in whole number
    arithmetic can be applied to newly unitized
    objects.
  • Grade 4
  • ¼ 1/4 ¼ ¾
  • Add fractions with like denominators
  • 3 x ¼ ¾
  • Multiply whole number times a fraction n(a/b)
    (na)/b

51
Grade 5
  1. Add and subtract fractions with unlike
    denominators using multiplication by n/n to
    generate equivalent fractions and common
    denominators
  2. 1/b 1 divided by b fractions can express
    division
  3. Multiply and divide fractions

52
Fraction Equivalence Grade 3
  • Fractions of areas that are the same size, or
    fractions that are the same point (length from 0)
    are equivalent
  • recognize simple cases ½ 2/4 4/6 2/3
  • Fraction equivalents of whole numbers 3 3/1,
    4/4 1
  • Compare fractions with same numerator or
    denominator based on size in visual diagram

53
Fraction equivalence Grade 4
  • Explain why a fraction a/b na/nb using visual
    models generate equivalent fractions
  • Compare fractions with unlike denominators by
    finding common denominators explain on visual
    model based on size in visual diagram

54
Fraction equivalence Grade 5
  • Use equivalent fractions to add and subtract
    fractions with unlike denominators

55
Fraction Item
  • 4/5 is closer to 1 than 5/4. Show why this is
    true on a number line.

56
Fraction Item
  • 4/5 is closer to 1 than 5/4. Show why this is
    true on a number line.

57
Students perform calculations and solve problems
involving addition, subtraction,and simple
multiplication and division of fractions and
decimals
  • 2.1 Add, subtract, multiply, and divide with
    decimals add with negative integers subtract
    positive integers from negative integers and
    verify the reasonableness of the results.
  • 2.2 Demonstrate proficiency with division,
    including division with positive decimals and
    long division with multidigit divisors.

58
Students perform calculations and solve problems
involving addition, subtraction, and simple
multiplication and division of fractions and
decimals
  • 2.3 Solve simple problems, including ones
    arising in concrete situations, involving the
    addition and subtraction of fractions and mixed
    numbers (like and unlike denominators of 20 or
    less), and express answers in the simplest form.
  • 2.4 Understand the concept of multiplication and
    division of fractions.
  • 2.5 Compute and perform simple multiplication and
    division of fractions and apply these procedures
    to solving problems.

59
Use equivalent fractions as a strategy to add and
subtract fractions.
  • 1. Add and subtract fractions with unlike
    denominators (including mixed numbers) by
    replacing given fractions with equivalent
    fractions in such a way as to produce an
    equivalent sum or difference of fractions with
    like denominators. For example, 2/3 5/4 8/12
    15/12 23/12. (In general, a/b c/d (ad
    bc)/bd.)

60
Use equivalent fractions as a strategy to add and
subtract fractions.
  • 2. Solve word problems involving addition and
    subtraction of fractions referring to the same
    whole, including cases of unlike denominators,
    e.g., by using visual fraction models or
    equations to represent the problem. Use benchmark
    fractions and number sense of fractions to
    estimate mentally and assess the reasonableness
    of answers. For example, recognize an incorrect
    result 2/5 1/2 3/7, by observing that 3/7 lt
    1/2.

61
CA CST grade 5 item
  • It takes Suzanne 1/6 hour to walk to the
    playground and 1/3 hour to walk from the
    playground to school. How much time does it take
    Suzanne to walk to the playground and then to
    school?
  • A 2/9 hour
  • B 1/3 hour
  • C 1/2 hour
  • D 2/3 hour

62
Solving equations vs. functions
  • .25a - 3 0 f(a) .25a - 3
  • a2 5a 0 f(a) a2 5a
  • ? f(a) 2a

63
CA CST 5th grade
  • Yoshi spent 1 and 1/3 hours reading and ¾ hour
    doing chores. How many total hours did Yoshi
    spend on these activities?
  • A 1 1/3
  • B 1 4/7
  • C 2 1/12
  • D 2 1/6

64
(No Transcript)
65
(No Transcript)
66
(No Transcript)
67
(No Transcript)
68
(No Transcript)
69
(No Transcript)
70
(No Transcript)
71
(No Transcript)
72
(No Transcript)
73
The most important ideas in the CCSS mathematics
that need attention.
  1. Properties of operations their role in
    arithmetic and algebra
  2. Mental math and algebra vs. algorithms
  3. Units and unitizing
  4. Operations and the problems they solve
  5. Quantities-variables-functions-modeling
  6. Number-Operations-Expressions-Equation
  7. Modeling
  8. Practices

74
Progression quantities and measurement to
variables and functions
75
K - 5 6
- 8 9 - 12

Equal Partitioning, division
proportional and linear relationships
multiplication
Measurement of quantities, units
Systems of linear equations
Unit Rate
Number line, graphs
slope
ratio
76
Representing quantities with expressions
77
Mental math
  • 72 -29 ?
  • In your head.
  • Composing and decomposing
  • Partial products
  • Place value in base 10
  • Factor X2 4x 4 in your head

78
Operations and the problems they solve
  • Tables 1 and 2 on pages 88 and 89

79
Properties of Operations
  • Also called rules of arithmetic , number
    properties

80
From table 2 page 89
  • a b ?
  • a ? p, and p a ?
  • ? b p, and p b ?
  • 1.Play with these using whole numbers,
  • 2.make up a problem for each.
  • 3. substitute (x 1) for b

81
Nine properties are the most important
preparation for algebra
  • Just nine foundation for arithmetic
  • Exact same properties work for whole numbers,
    fractions, negative numbers, rational numbers,
    letters, expressions.
  • Same properties in 3rd grade and in calculus
  • Not just learning them, but learning to use them

82
Using the properties
  • To express yourself mathematically (formulate
    mathematical expressions that mean what you want
    them to mean)
  • To change the form of an expression so it is
    easier to make sense of it
  • To solve problems
  • To justify and prove

83
Properties are like rules, but also like rights
  • You are allowed to use them whenever you want,
    never wrong.
  • You are allowed to use them in any order
  • Use them with a mathematical purpose

84
Properties of addition
Associative property of addition (a b) c a (b c) (2 3) 4 2 (3 4)
Commutative property of addition a b b a 2 3 3 2
Additive identity property of 0 a 0 0 a a 3 0 0 3 3
Existence of additive inverses For every a there exists a so that a (a) (a) a 0. 2 (-2) (-2) 2 0
85
Properties of multiplication
Associative property of multiplication (a x b) x c a x (b x c) (2 x 3) x 4 2 x (3 x 4)
Commutative property of multiplication a x b b x a 2 x 3 3 x 2
Multiplicative identity property of 1 a x 1 1 x a a 3 x 1 1 x 3 3
Existence of multiplicative inverses For every a ? 0 there exists 1/a so that a x 1/a 1/a x a 1 2 x 1/2 1/2 x 2 1
86
Linking multiplication and addition the ninth
property
  • Distributive property of multiplication over
    addition
  • a x (b c) (a x b) (a x c)
  • a(bc) ab ac

87
Find the properties in multiplication table
patterns
  • There are many patterns in the multiplication
    table, most of them are consequences of the
    properties of operations
  • Find patterns and explain how they come from the
    properties.
  • Find the distributive property patterns

88
Grade level examples
  • 3 packs of soap
  • 4 dealing cards
  • 5 sharing
  • 6 money
  • 7 lengths (fractions)
  • 8 times larger ()

89
K -5 6
8 9 - 12

Quantity and measurement
Ratio and proportional relationships
Operations and algebraic thinking
Functions
Expressions and Equations
Modeling (with Functions)
Modeling Practices
90
K -2 3
- 6 7 - 12

Equal Partitioning
Rates, proportional and linear relationships
Unitizing in base 10 and in measurement
Rational number
Fractions
Number line in Quantity and measurement
Properties of Operations
Rational Expressions
91
Functions and Solving Equations
  • Quantities-variables-functions-modeling
  • Number-Operations-Expressions-Equation

92
Take the number apart?
  • Tina, Emma, and Jen discuss this expression
  • 5 1/3 x 6
  • Tina I know a way to multiply with a mixed
    number, like 5 1/3 , that is different from the
    one we learned in class. I call my way take the
    number apart. Ill show you.

93
Which of the three girls do you think is right?
Justify your answer mathematically.
  • First, I multiply the 5 by the 6 and get 30.
  • Then I multiply the 1/3 by the 6 and get 2.
    Finally, I add the 30 and the 2, which is 32.
  • Tina It works whenever I have to multiply a
    mixed number by a whole number.
  • Emma Sorry Tina, but that answer is wrong!
  • Jen No, Tinas answer is right for this one
    problem, but take the number apart doesnt work
    for other fraction problems.

94
What is an explanation?
  • Why you think its true and why you think it
    makes sense.
  • Saying distributive property isnt enough, you
    have to show how the distributive property
    applies to the problem.

95
Example explanation
  • Why does 5 1/3 x 6 (6x5) (6x1/3) ?
  • Because
  • 5 1/3 5 1/3
  • 6(5 1/3)
  • 6(5 1/3)
  • (6x5) (6x1/3) because a(b c) ab ac

96
Mental math
  • 72 -29 ?
  • In your head.
  • Composing and decomposing
  • Partial products
  • Place value in base 10
  • Factor X2 4x 4 in your head

97
Locate the difference, p - m, on the number line
p
m
0
1
98
For each of the following cases, locate the
quotient p/m on the number line
p
m
0
1
m
0
p
1
p
m
0
1
m
1
p
0
99
Misconceptions about misconceptions
  • They werent listening when they were told
  • They have been getting these kinds of problems
    wrong from day 1
  • They forgot
  • The other side in the math wars did this to the
    students on purpose

100
More misconceptions about the cause of
misconceptions
  • In the old days, students didnt make these
    mistakes
  • They were taught procedures
  • They were taught rich problems
  • Not enough practice

101
Maybe
  • Teachers misconceptions perpetuated to another
    generation (where did the teachers get the
    misconceptions? How far back does this go?)
  • Mile wide inch deep curriculum causes haste and
    waste
  • Some concepts are hard to learn

102
Whatever the Cause
  • When students reach your class they are not blank
    slates
  • They are full of knowledge
  • Their knowledge will be flawed and faulty, half
    baked and immature but to them it is knowledge
  • This prior knowledge is an asset and an
    interference to new learning

103
Second grade
  • When you add or subtract, line the numbers up on
    the right, like this
  • 23
  • 9
  • Not like this
  • 23
  • 9

104
Third Grade
  • 3.24 2.1 ?
  • If you Line the numbers up on the right like
    you spent all last year learning, you get this
  • 3.2 4
  • 2.1
  • You get the wrong answer doing what you learned
    last year. You dont know why.
  • Teach line up decimal point.
  • Continue developing place value concepts

105
Research on Retention of Learning Shell Center
Swan et al
106
Lesson Units for Formative Assessment
  • Concept lessonsProficient students expect
    mathematics to make sense
  • To reveal and develop students interpretations
    of significant mathematical ideas and how these
    connect to their other knowledge.
  • Problem solving lessonsThey take an active
    stance in solving mathematical problems
  • To assess and develop students capacity to apply
    their Math flexibly to non-routine, unstructured
    problems, both from pure math and from the real
    world.

107
Mathematical Practices Standards
  • Make sense of complex problems and persevere in
    solving them.
  • Reason abstractly and quantitatively
  • Construct viable arguments and critique the
    reasoning of others.
  • 4. Model with mathematics.
  • 5. Use appropriate tools strategically.
  • Attend to precision
  • Look for and make use of structure
  • 8. Look for and express regularity in repeated
    reasoning.
  • College and Career Readiness Standards for
    Mathematics

108
Mathematical Content Standards
  • Number Quantity
  • Algebra
  • Functions
  • Modeling
  • Statistics and Probability
  • Geometry

109
Concept focused v Problem focused
110
Optimization Problems Boomerangs
  • Projector Resources

111
(No Transcript)
112
Evaluating Sample Responses to Discuss
  • What do you like about the work?
  • How has each student organized the work?
  • What mistakes have been made?
  • What isn't clear?
  • What questions do you want to ask this student?
  • In what ways might the work be improved?

113
Alexs solution
114
Dannys solution
115
Jeremiahs solution
116
Tanya's solution
117
Progressions (http//ime.math.arizona.edu/pro
gressions/) Illustrative Mathematics Project
(http//illustrativemathematics.org). Technical
manual NCTM-AMTE-NCSM-ASSM task force (see
description at http//commoncoretools.wordpre
ss.com NCTM sample tasks for reasoning and
sense-making, http//www.nctm.org/hsfocus Mc
Callum blog, Tools for the Common Core,
http//commoncoretools.wordpress.com Daro video
and slides serpinstitute.org
118
Making Sense of Word Problems
119
Word Problem from popular textbook
  • The upper Angel Falls, the highest waterfall on
    Earth, are 750 m higher than Niagara Falls. If
    each of the falls were 7 m lower, the upper Angel
    Falls would be 16 times as high as Niagara Falls.
    How high is each waterfall?

120
Imagine the Waterfalls Draw
121
Diagram it
122
The Height of Waterfalls
123
Heights
124
Height or Waterfalls?
750 m.
125
Heights we know
750 m.
7 m.
126
Heights we know and dont
750 m.
d
d
7 m.
7 m.
127
Heights we know and dont
750 m.
d
d
7 m.
7 m.
Angel 750 d 7 Niagara d 7
128
Same height referred to in 2 ways
16d 750 d
750 m.
16d
d
d
7 m.
7 m.
Angel 750 d 7 Niagara d 7
129
d ?
16d 750 d 15d 750 d 50
750 m.
16d
d
d
7 m.
7 m.
Angel 750 50 7 807 Niagara 50 7 57
Angel 750 d 7 Niagara d 7
130
Activate prior knowledge
  • What knowledge?
  • Have you ever seen a waterfall?
  • What does water look like when it falls?

131
Take the number apart?
  • Tina, Emma, and Jen discuss this expression
  • 5 1/3 x 6
  • Tina I know a way to multiply with a mixed
    number, like 5 1/3 , that is different from the
    one we learned in class. I call my way take the
    number apart. Ill show you.

132
Which of the three girls do you think is right?
Justify your answer mathematically.
  • First, I multiply the 5 by the 6 and get 30.
  • Then I multiply the 1/3 by the 6 and get 2.
    Finally, I add the 30 and the 2, which is 32.
  • Tina It works whenever I have to multiply a
    mixed number by a whole number.
  • Emma Sorry Tina, but that answer is wrong!
  • Jen No, Tinas answer is right for this one
    problem, but take the number apart doesnt work
    for other fraction problems.

133
What is an explanation?
  • Why you think its true and why you think it
    makes sense.
  • Saying distributive property isnt enough, you
    have to show how the distributive property
    applies to the problem.

134
Example explanation
  • Why does 5 1/3 x 6 (6x5) (6x1/3) ?
  • Because
  • 5 1/3 5 1/3
  • 6(5 1/3)
  • 6(5 1/3)
  • (6x5) (6x1/3) because a(b c) ab ac

135
In the Description box
  • Today I valued
  • Id like to spend more time on
  • Make sure to put the correct date June 29, 2011
Write a Comment
User Comments (0)
About PowerShow.com