HIGHLINE SCHOOL DISTRICT MATH OLYMPIAD March 25, 2000

2

 
 


Cell Phone Problem Scoring Guide

CORRECT ANSWER:

Points

Look for the following:

4

One or both of the following statements

         If Sally makes 84 or more calls per month she should choose the corporate plan.

         If Sally makes 83 or fewer calls per month she should choose the individual plan

0

         Answer is not correct.

 

PROBLEM UNDERSTANDING

What did you notice about patterns?

Points

Look for the following:

4

         Notices that for few calls individual plan is better than corporate

         Noticed that Sally saves 30 cents on each corporate call but pays $25 extra per month. Recognizes that it is necessary to know how many 30 cent calls could be made for $25 to determine the cross-over point from individual to corporate.

3

         Notices that for few calls individual plan is better than corporate

         Notices that for many calls corporate plan is better

         Recognizes that the change for each additional call is constant

2

         Notices that for few calls individual plan is better than corporate

         Notices that for many calls corporate plan is better

         Did not extend the pattern any further

1

         The task is misunderstood

0

         No attempt at response.

 

STRATEGY

Students were asked: What strategy did you use?

Points

Look for the following:

4

         A valid strategy is used: use a rule, guess and check, make a table, write equations, draw a graph

3

         A valid strategy is used, but may have breakdown in logic.

2

         Strategy was applied , but steps may be missing

         Labels may be missing or directions may not have completely been followed

1

         Strategy was not explained according to directions, or the reasoning is confused (but there was one)

0

         No attempted strategy, just answers

 


 

COMMUNICATION

Students were told: Explain your reasoning using sentences, pictures. or tables

Points

Look for the following:

4

         Described strategy and solution clearly and completely, step-by-step, with all steps included

         Appropriate labels, terminology, and symbols are used

3

         Described strategy and solution, but steps may be missing from the explanation. The evaluator is required to infer that intermediate steps were performed correctly

         Appropriate labels, terminology, and symbols are used

2

         Strategy was described, but steps may be missing or out of order

1

         Strategy was not explained according to directions, or reasoning is confusing

0

         No attempt to explain

 

 

REASONABLE RESULT

Student was asked: How do you know your answer was reasonable? Did you work the problem a different way?

Points

Look for the following:

4

         Review used a different approach to support the result

         Review demonstrated correctness of work (showed work)

         Explained why the result makes sense

3

         The result was checked using the same approach as initially

2

         A statement is make about checking the result without supporting information

1

         A check was done but it was not valid

0

         No attempt was made to demonstrate the reasonableness of the result