CCSS Mathematics Assessment Task

Stamps

Grade Level: 2
Mathematics Domain and Cluster:
Domain: Number and Operations in Base Ten
Cluster: Use place value understanding and properties of operations to add and subtract.
Common Core standard(s) being assessed (if the task is intended to assess only one part of the standard, underline that part of the standard):
2.NBT.5 Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
2.NBT.9 Explain why addition and subtraction strategies work, using place value and the properties of operations. (Explanations may be supported by drawings or objects.)
Student Materials:
·  Relationship Between Addition and Subtraction Assessment Sheet
·  Pencil
Differentiation Option:
·  Base Ten manipulatives
Teacher Materials:
·  Base Ten manipulatives (Optional)
Directions (for teacher to administer assessment task):
·  Pass out Relationship Between Addition and Subtraction assessment sheet (1 per student)
·  Tell students, “Read the problem that Mr. Harris gave his students. Then, solve Maya and Ben’s equations using a strategy. Finally, explain in words if Maya and Ben both get the same answer using different equations and explain why.”
·  Read prompt aloud to students.
·  Remind students, “ Do not forget to solve Maya and Ben’s equations and explain in words if Maya and Ben get the same answer using different equations.”
·  Have students work independently on the task.
Differentiation Options:
·  Allow students to use Base Ten manipulatives if needed.
Prompt:
See attachment
Correct or Sample Model Answer:
Maya’s Strategy
61 – 28 = ______
61 – 20 = 41
41 – 1 = 40
40 – 7 = 33 stamps / Ben’s Strategy
28 + ______= 61
28 + 2 = 30
30 + 30 = 60
60 + 1 = 61
2 + 30 + 1 = 33 stamps
Maya and Ben both got the same answer using subtraction and addition because addition and subtraction undo each other. Maya was taking away 28 to find out how many more stamps Emi had and Ben added up from 28 to 61 to find out how many stamps Jake needed to get to 61.
Scoring Guide/Rubric (a score should be awarded for each criterion below)
Criteria (CCSS code) / 0 points / 1 Point / 2 Point
Fluently add and subtract within 100 using strategies based on place value and properties of operations. (2.NBT.5) / Attempts to solve both problems and has major misconceptions OR is unable to solve the problem. / Solves one of the two problems correctly but the other problem has some minor misconceptions OR solves both problems but has minor misconceptions. / Solves both problems accurately using:
-Place value
-Properties of operations
Explain why addition and subtraction strategies work, using place value and the properties of operations. Explanations may be supported by drawings or objects.
(2.NBT.9) / Explains with major misconceptions OR is unable to explain why both answers should be the same. / Explains why both answers should be the same with minor errors. / Clearly explains why both answers should be the same in the two problems.

Maya and Ben’s Problem

Second Grade Mathematics Assessment

Problem:
Mr. Harris read his class the following problem.
Jake had 28 stamps. Emi had 61 stamps. How many more stamps does Emi have than Jake?
Maya said, “I can solve the problem like this: 61 – 28 = ______.”
Ben said, “I can solve the problem like this: 28 + ______= 61.”
Are Maya and Ben correct? Solve the problems using both equations.
Maya’s Strategy:
61 – 28 = ______/ Ben’s Strategy:
28 + ______= 61
Did Maya and Ben both get the same answer using different equations? Explain why.
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