Georgia Department of Education
Common Core Georgia Performance Standards Framework
Third Grade Mathematics x Unit 2
PERFORMANCE TASK: “HOW MANY TENS?”
Adapted from NZ Maths
This task further relates multiples of ten to place value by giving students the
opportunity to build onto the concept that 10 tens equal one hundred, and 10 hundreds
equal one thousand.
STANDARDS FOR MATHEMATICAL CONTENT
MCC.3.NBT.3 Multiply one-digit whole numbers by multiples of 10 in the range 10–90 (e.g., 9
× 80, 5 × 60) using strategies based on place value and properties of operations.
STANDARDS OF MATHEMATICAL PRACTICE (SMP)
1. Make sense of problems and persevere in solving them.
2. Reason abstractly and quantitatively.
3. Construct viable arguments and critique the reasoning of others.
6. Attend to precision.
7. Look for and make use of structure.
8. Look for and express regularity in repeated reasoning.
BACKGROUND KNOWLEDGE
This task is designed to develop the concept of what happens to a number when multiplied by a
multiple of ten. To help build context, the teacher may read 100 Hungry Ants by J. Pinzces.
Students need to know that 10 tens make 100 and 10 hundreds make one thousand.
COMMON MISCONCEPTION
It is important to address any misconceptions that students may have with “just adding zeros”.
Students need to be able to think in terms of ___ groups of ____ tens.
Additionally, student misconceptions with this task may be with their understanding of place
value. When working with longs, students may see the group as a group of 1 instead of a group
of 10. For example, when counting 5 longs the student may count them as “1, 2, 3, 4, 5” with a
total of 5 objects instead of counting them as “10, 20, 30, 40, 50” or “5 groups of 10” with a total
of 50. It is important for students to have this understanding of the long consisting of 10 units.
ESSENTIAL QUESTIONS
x
x
How can I model multiplication by ten?
How is multiplying by ten related to place value?
MATHEMATICS y GRADE 3y UNIT 2: Operations and Algebraic Thinking: the Relationship Between Multiplication and Division
Georgia Department of Education
Dr. John D. Barge, State School Superintendent
July 2013 y Page 81 of 162
All Rights Reserved
Georgia Department of Education
Common Core Georgia Performance Standards Framework
Third Grade Mathematics x Unit 2
MATERIALS
x
x
Money Manipulatives
“How many 10s” recording sheet
GROUPING
Students should work in groups of 3 to 4 members.
NUMBER TALK
By now number talks should be incorporated into the daily math routine. Continue utilizing the
different strategies in number talks and revisiting them based on the needs of your students. In
addition Catherine Fosnot has developed “strings” of numbers that could be included in a
number talk to further develop mental math skills. (See Minilessons for Early Multiplication and
Division by Willem Uittenbogaard and Catherine Twomey Fosnot (2007).
TASK DESCRIPTION, DEVELOPMENT AND DISCUSSION
Part I (SMP 1, 3, and 6)
Read the book, 100 Hungry Ants by J. Pinzces to your students. During strategic points
throughout the book, stop to discuss how the number 100 can be built or created from different
groups of ten. (This is a perfect “anchor chart” opportunity!) Facilitate a classroom discussion
about tens and hundreds to assess prior knowledge, and use this as a platform for a brief minilesson (if needed). Have the students work with their small groups to investigate, model (very
important), and figure out the following problems:
1. What are all of the possible ways the ants could have lined up (by multiples of 10) to
reach the picnic?
2. What would have been the QUICKEST way for the ants to march to the picnic so they
could have gotten there before all of the food was gone?
Part II (SMP 1, 2, 6, 7, and 8)
Read the scenario to the students.
Problem: The Bank of Mathematics has run out of $100 bills. Alison wants to withdraw
$300 in $10 dollar bills. How many $10 dollar bills does she get? Can you figure out
how many $10 bills she will need with different amounts such as $600 or $900?
Students will record answers in the “How Many Tens” table.
Repeat the same concept using the scenario below and $10 and $1 bills.
MATHEMATICS y GRADE 3y UNIT 2: Operations and Algebraic Thinking: the Relationship Between Multiplication and Division
Georgia Department of Education
Dr. John D. Barge, State School Superintendent
July 2013 y Page 82 of 162
All Rights Reserved
Georgia Department of Education
Common Core Georgia Performance Standards Framework
Third Grade Mathematics x Unit 2
Problem: The Bank of Mathematics has run out of $100 bills. Alison wants to withdraw
$256 in $10 and $1 bills. How many of each bill will she receive?
Students will record answers in “How Many Tens” table.
FORMATIVE ASSESSMENT QUESTIONS
x
x
x
How did you determine how many tens to give?
What if you didn’t have any tens, what could you use?
How does Multiplication help you determine the amount of tens needed to withdraw?
DIFFERENTIATION
Extension
x Students can determine the number of ones, then tens, then hundreds it would take to
reach various student-suggested amounts. Organize the information into a student-created
table, look for patterns, and explain what you see.
Intervention (SMP 4 and 5)
x Students can complete this activity with smaller amounts of money.
x Students can complete only the first part of the recording sheet.
x Students can complete the second part of the recording sheet with amounts rounded to the
nearest hundred.
x Students should be given Base Ten blocks or money to help them make sense of the
problem.
MATHEMATICS y GRADE 3y UNIT 2: Operations and Algebraic Thinking: the Relationship Between Multiplication and Division
Georgia Department of Education
Dr. John D. Barge, State School Superintendent
July 2013 y Page 83 of 162
All Rights Reserved
Georgia Department of Education
Common Core Georgia Performance Standards Framework
Third Grade Mathematics x Unit 2
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Problem#1: The Bank of Mathematics has run out of $100 bills. Alison wants to withdraw $300
in $10 dollar bills. How many $10 dollar bills does she get? Can you figure out how many $10
bills she will need with different amounts such as $600 or $900?
Withdraw
$300.00
$600.00
$900.00
$700.00
$500.00
$200.00
$800.00
How Many Tens?
How many $10.00 bills?
Question for reflection:
How did you determine the amount of $10.00 bills needed?
______________________________________________________________________________
______________________________________________________________________________
Problem#2: The Bank of Mathematics has run out of $100 bills. Alison wants to
withdraw $256 in $10 bills. How many of each bill will she receive?
How Many Tens and Ones?
Withdraw
$10.00
$256.00
$352.00
$468.00
$853.00
$523.00
$631.00
$750.00
$1.00
Question for reflection:
How did you determine the amount of $1.00 and $10.00 bills needed?
______________________________________________________________________________
______________________________________________________________________________
Extension Problem:
Tickets to a concert cost $100 each. How many tickets could you buy if you have $3215?
MATHEMATICS y GRADE 3y UNIT 2: Operations and Algebraic Thinking: the Relationship Between Multiplication and Division
Georgia Department of Education
Dr. John D. Barge, State School Superintendent
July 2013 y Page 84 of 162
All Rights Reserved