2.OA.3/ OPERATIONS AND ALGEBRAIC THINKING
MATH DOMAIN
2.OA.3/ OPERATIONS AND ALGEBRAIC THINKING
Grade 2
Math Cluster
Work with
equal groups
of objects to
gain
foundations
for
multiplication.
August 2013
Math Standard
Mathematic Practices
2.OA.3 Determine
whether a group of
objects (up to 20) has an
odd or even number of
members, e.g. by pairing
objects or counting them
by 2s; write an equation
to express an even
number as a sum of two
equal addends [doubles].
2. Reason abstractly and quantitatively.
3. Construct viable arguments and
critique the reasoning of others.
4. Model with mathematics.
5. Use appropriate tools strategically.
6. Attend to precision.
7. Look for and make use of structure.
8. Look for and express regularity in
repeated reasoning.
Reporting Standard
Trimester 1
Trimester 2
Trimester 3
Operations: Model and describe
multiplication as joining sets of equal
parts.
Odd or even
(tested)
Doubles to 10
(tested)
Doubles to 20
(tested)
Clarify Standard
 With any given number within 20, the number is even if the given number can be
broken into fair shares. (doubles)
 With any given number within 20, the number is odd if the given number cannot be
broken into fair shares. (not doubles)
 Use of manipulatives and/or drawings appropriate.
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2.OA.3/ OPERATIONS AND ALGEBRAIC THINKING
Task Analysis
1.OA.5 Relate counting to addition and subtraction e.g., by counting on 2 to add two).
Learning Tasks:
 Count by two’s.
2.OA.3 Determine whether a group of objects (up to 20) has an odd or even number of
members, e.g. by pairing objects or counting them by 2s; write an equation to express an
even number as a sum of two equal addends [doubles].
Vocabulary
Prior

Doubles
Explicit






Addend
Sum
Odd
Even
Doubles
Fair shares
2.OA.3 Sample Assessment Items earning a “3” in reporting system
 Draw 15 balloons. Put the balloons into pairs. Do you have an even or odd amount
of balloons?
 Draw ten marbles that you have split into two even groups. Write an equation.
 Tell if these numbers are even or odd: 8 / 20 / 17 / 9
Assessment Rubric
1
No evidence of a strategy.
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2.OA.3/ OPERATIONS AND ALGEBRAIC THINKING
2
Evidence that the student used a correct strategy but answered incorrectly. OR
The student answered correctly with no evidence of strategy.
3
Evidence that the student used a correct strategy, and correct equation, and
answered correctly.
4
On a level 4 question: Evidence that the student used a correct strategy, and
correct equation, and answered correctly.
2.OA.3 Sample Assessment Items earning a “4” in reporting system
Juan is sharing cupcakes with his classmates. Each box holds 12 cupcakes. His mom
bought 2 packages of chocolate cupcakes and I package of white cupcakes. There are 27
kids in Juan’s class (including Juan).
 If each child gets a cupcake, will the number of extra cupcakes be even or odd?
 If there are 15 girls in Juan’s class and they all took a chocolate cupcake, and half
the boys took chocolate and half the boys took vanilla.
 How many extra chocolate cupcakes are there and is that number odd or even?
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