CCGPS Mathematics
Fifth Grade Update Webinar
Unit 3: Multiplying and Dividing with Decimals
October 14, 2013
Update presentations are the result of collaboration between members of 2012
and 2013 Unit Review and Revision Teams and classroom teachers
Microphone and speakers can be configured by going to:
Tools – Audio – Audio setup wizard
Turtle Toms- tgunn@doe.k12.ga.us
Elementary Mathematics Specialist
These materials are for nonprofit educational purposes only. Any other use may
constitute copyright infringement.
Today’s presenters
 Emily Heck – Gwinnett County
 Trudy Ives – Gwinnett County
 Michelle Parker - Gordon County
 Michael Wiernicki - Henry County
Webinar Guide
 Unit 3 Overview
 Critical areas within this unit
 Content standards
 Practice standards
 Decimal number talks
 Changes to Unit 3 tasks
 Resources
Critical Areas in 5th Grade
Unit 3 Falls under the 2nd Critical Area
Students should be given ample
opportunities to keep their unit 3 skills
sharp throughout the remainder of the
year.
Unit 3 Content, Strategies and Misconceptions
Understand the place value system.
 MCC5.NBT.2 Explain patterns in the number of zeros of the product when
multiplying a number by powers of 10, and explain patterns in the placement of
the decimal point when a decimal is multiplied or divided by a power of 10. Use
whole-number exponents to denote powers of 10.
Content:
o As students multiply and divide decimals by powers of tens, they should
notice a pattern occurring in the number of zeros in the product or quotient,
as well as a pattern in the placement of the decimal point in the resulting
product or quotient.
o Students need to explain why these patterns are occurring when a decimal
number is multiplied or divided by a power of ten.
o Students should become aware that 1, 10, 100 and 1,000 are powers of ten
and that these numbers can be expressed as whole number exponents.
Unit 3 Content, Strategies and Misconceptions
 MCC5.NBT.2 Explain patterns in the number of zeros of the product when
multiplying a number by powers of 10, and explain patterns in the placement of the
decimal point when a decimal is multiplied or divided by a power of 10. Use wholenumber exponents to denote powers of 10.
Strategies:
o
Elicit student’s prior knowledge about MCC5.NBT.1 – recognizing that in a multidigit number, a digit in one place represents 10 times as much as it represents in
the place to its right and one tenth of what it represents in the place to its left.
o
Use base ten blocks or hundreds grids to help students create models or
representations of problems where exponents are used. Change the value of the
base ten blocks to create decimal numbers instead of whole numbers.
o
Compare and contrast the process of multiplying and dividing whole numbers by
powers of ten to multiplying and dividing decimal numbers by powers of ten.
Help students see the similarities and differences between the two.
Unit 3 Content, Strategies and Misconceptions
Unit 3 Content, Strategies and Misconceptions
Unit 3 Content, Strategies and Misconceptions
 MCC5.NBT.2 Explain patterns in the number of zeros of the product when
multiplying a number by powers of 10, and explain patterns in the placement of
the decimal point when a decimal is multiplied or divided by a power of 10. Use
whole-number exponents to denote powers of 10.
Student Misconceptions:
o Students are familiar with how multiplying or dividing a whole number by a
power of ten affects a product or quotient. They visually see the zeros being
added to the product or being dropped from the quotient. Some students
take that knowledge and try to apply it to multiplying and dividing decimals
by powers of ten. Students need to be aware that while adding or dropping
zeros to the product or quotient may happen, it is also possible that they may
just see a shift in the decimal point in the product or quotient.
Unit 3 Content, Strategies and Misconceptions
Perform operations with multi-digit whole numbers and with decimals
to the hundredths.
 MCC5.NBT.7 Add, subtract, multiply, and divide decimals to hundredths,
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 and explain the reasoning
used.
Content:
o Students multiply and divide decimal numbers to the hundredths place.
o Students should develop an understanding of how the algorithm works
through the use of concrete models and representations.
o Students should make connections between the algorithm and partial
products and partial quotients.
Unit 3 Content, Strategies and Misconceptions
 MCC5.NBT.7 Add, subtract, multiply, and divide decimals to hundredths,
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 and explain the reasoning
used.
Strategies:
o Work with base ten blocks and decimal grids so that students connect
visually to the process of multiplying and dividing decimal numbers.
o Area models are also a very powerful tool for promoting student
understanding of decimal multiplication and division.
o Students can generate an estimate of the product or quotient to determine if
their exact answer is reasonable or not.
Unit 3 Content, Strategies and Misconceptions
Unit 3 Content, Strategies and Misconceptions
 MCC5.NBT.7 Add, subtract, multiply, and divide decimals to hundredths,
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 and explain the reasoning
used.
Student Misconceptions:
o Students’ prior experiences have led them to understand that when
multiplying whole numbers the product is always larger than the factors.
They also have experienced that dividing whole numbers always results in a
quotient that is smaller than the dividend. They may experience
disequilibrium when multiplying and dividing by decimal numbers because
these beliefs will no longer always be true.
Standards for
Mathematical
Practice
Number
Talks
Decimal Multiplication Number Talks
 Strategies for Multiplying Decimals
 Estimation
 Fractions and Decimals as Operators
 Associative & Commutative Properties
 Eliminating the Decimal / Maintaining Equivalence
 Partial Products
 Distributive Property
 Using Landmark Numbers (think money)
 Using Place Value
 Array models are an important tool used to develop
these strategies
Adapted from Number Talks by Sherry Parrish
Decimal Division Number Talks
 Strategies for Dividing Decimals
 Estimation
 Think multiplication / Find the missing factor
 Eliminating the decimal / Maintaining equivalence
 Student models are important here as well. The
models students choose to use show their level of
understanding of operations with decimals.
Adapted from Number Talks by Sherry Parrish
Unit 3 Tasks - Unchanged













Power-ful Exponents
What Comes Next?
Patterns-R-Us
Base Ten Activity
Missing Numbers
Multiplication Teasers
How Much Money?
Super Slugger Award
What’s My Rule?
Do You See an Error?
Road Trip
Teacher for a Day
Bargain Shopping
Task – Base 10 Activity
 MCC5.NBT.7
1. 4.8 x 3
Task – Base 10 Activity
 MCC5.NBT.7
1. 4.8 x 3
Task – Base 10 Activity
 MCC5.NBT.7
2. 2.1 x 5.4
Task – Base 10 Activity
 MCC5.NBT.7
5. 3.6 ÷ 1.2
Task – Base 10 Activity
 MCC5.NBT.7
4.83 ÷ 2.1
Revised Task - Place the Point
 MCC5.NBT.2 &
 MCC5.NBT.7
Revised Task - Number Puzzles
 MCC5.NBT.7
New Task - Multiplying and Dividing Decimals
 FAL – Formative Assessment Lesson
New Task - Multiplying and Dividing Decimals
New Task - Multiplying and Dividing Decimals
New Culminating Task – Field Trip
 MCC5.NBT.4 & MCC5.NBT.7
Resources
 K-5 Mathematics Wiki
http://ccgpsmathematicsk-5.wikispaces.com/
 OAS Formative Assessment Bank (NBT.2)
http://www.georgiaoas.org
 Illustrative Mathematics (NBT.2&7)
http://www.illustrativemathematics.org/standards/k8
 K-5 Math Teaching Resources (NBT.2)
http://www.k-5mathteachingresources.com/5th-grade-number-activities.html
 Learn Zillion
http://learnzillion.com/lessons
 Decimal Multiplication (change to multiplication, 1-3 grids, 10 rows, 10 columns)
http://my.hrw.com/math06_07/nsmedia/tools/Decimal_Fractions/Decimal_Fract
ions.swf
What do you believe about learning?
With which statements do you agree?
1. My intelligence is something very basic
about me which I can’t change very
much.
2. I can learn new things, but I can’t really
change how intelligent I am.
3. No matter how much intelligence I have,
I can always change it quite a bit.
4. I can always substantially change how
intelligent I am.
What do you believe about learning?
What do you believe about learning?
What do you believe about learning?
Want more?
http://mindsetonline.com/whatisit/ab
Why RTI?
Graphic from-
http://www.rti4success.org/
Why RTI?
• What does it mean to be
mathematically fluent?
• What prevents kids from
becoming mathematically
fluent?
• How can we support
mathematical fluency
development?
GOT RTI?
GET STRATEGIES.
The What?
• GloSS
Global Strategy Stage
• IKAN
Individual Knowledge Assessment of Number
• http://schoolwires.henry.k12.ga.us/Page/33480
• http://nzmaths.co.nz/mathematics-assessment
• http://prezi.com/1goefix7aclq/math-assessment-gloss-ikan/
Why?
GET STRATEGIES.
GET STRATEGIES.
GET STRATEGIES.
GET STRATEGIES.
Want more?
http://prezi.com/h5xrmvdsxhyy/understanding-the-gloss-and-ikan-assessment-forsyth/
Feedback
http://ccgpsmathematicsk-5.wikispaces.com/
Turtle Toms- tgunn@doe.k12.ga.us
Elementary Mathematics Specialist
Thank You!
Please visit http://ccgpsmathematicsk-5.wikispaces.com/ to share your feedback, ask
questions, and share your ideas and resources!
Please visit https://www.georgiastandards.org/Common-Core/Pages/Math.aspx
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Follow @GaDOEMath
Turtle Toms
Program Specialist (K-5)
tgunn@doe.k12.ga.us
These materials are for nonprofit educational purposes only.
Any other use may constitute copyright infringement.