




Massachusetts Comprehensive Assessment System
2014, Grade 7 Mathematics
Question 10: OpenResponse 

Reporting Category: The Number System Standard: Mathematics.7.NS.1.01  Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers; represent addition and subtraction on a horizontal or vertical number line diagram.

Ethan plotted points E, F, G, H, and I on a number line, as shown below.  Which two points that Ethan plotted represent numbers that have a sum of 0? Show or explain how you got your answer.
 Write an equation using subtraction that could be used to find d, the distance, in units, between point E and point I.
 Solve the equation that you wrote in part (b). Show or explain how you got your answer.
Ethan wrote the expression below to represent the distance between point G and point H. What is the value of Ethan’s expression?
 Explain how you know Ethan’s expression is equivalent to the distance between point G and point H.

Scoring Guide and Sample Student Work Select a score point in the table below to view the sample student response.
Score  Description 
4 
The student response demonstrates an exemplary understanding of the Number System concepts involved in applying and extending previous understandings of addition and subtraction to add and subtract rational numbers and representing addition and subtraction on a horizontal number line diagram. The student identifies two numbers on a number line that have a sum of zero, and writes and solves an equation that could be used to find the distance between two points on the number line. 
4 
3 
The student response demonstrates a good understanding of the Number System concepts involved applying and extending previous understandings of addition and subtraction to add and subtract rational numbers and representing addition and subtraction on a horizontal number line diagram. Although there is significant evidence that the student was able to recognize and apply the concepts involved, some aspect of the response is flawed. As a result the response merits 3 points. 
2 
The student response demonstrates a fair understanding of the Number System concepts involved in applying and extending previous understandings of addition and subtraction to add and subtract rational numbers and representing addition and subtraction on a horizontal number line diagram. While some aspects of the task are completed correctly, others are not. The mixed evidence provided by the student merits 2 points. 
1 
The student response demonstrates a minimal understanding of the Number System concepts involved in applying and extending previous understandings of addition and subtraction to add and subtract rational numbers and representing addition and subtraction on a horizontal number line diagram. 
0 
The student response contains insufficient evidence of an understanding of the Number System concepts involved in applying and extending previous understandings of addition and subtraction to add and subtract rational numbers and representing addition and subtraction on a horizontal number line diagram to merit any points. 
Note: There are 2 sample student responses for Score Point 4.
Grade 7 Mathematics
 Question 10: The Number System
 Question 18: Statistics and Probability
Return to the MCAS 2014 Student Work Directory
Last Updated: March 21, 2014


