Getting Started 
Misconception/Error The student is unable to determine the probability of either event. 
Examples of Student Work at this Level The student says both probabilities are 50% (because either someone gets the defective monitorÂ or not).Â
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The student does not take all computers into account but gives an answer of:
 The probability that the defective monitorÂ is assigned to Sally is one out of six (because there are six monitors at each hub) or one out of four (because there are four hubs).
 The probability that the defective monitorÂ is assigned to a boy at Hub A is three out of six (because there are three boys out of six students at Hub A).
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Questions Eliciting Thinking How did you determine your probabilities?
How many favorable outcomes are there? How many possible outcomes are there?
How can you represent probability in fraction form? Should the total number of outcomes be the numerator or denominator? Why? 
Instructional Implications Review the meaning of probability and how it is calculated. Explain that the probability of an event is the number of outcomes favorable to that event compared to the total number of outcomes. Use a variety of manipulatives (e.g., coins, number cubes, and spinners) to demonstrate how probabilities are calculated. Clearly describe each possible outcome, the total number of outcomes, the outcomes favorable to a particular event, and the number of outcomes favorable to that event. Guide the student to calculate specific probabilities and to write the probabilities in multiple forms: fraction, decimal, and percent. Remind the student that the probability of an event is a number between zero and one (or 0% and 100%). Consider implementing CPALMS Lesson Plan A Roll of the Dice (ID 34343) or Marble Mania (ID 4732), to help students understand probability of simple events. 
Making Progress 
Misconception/Error The student is unable to determine the probability of a compound event. 
Examples of Student Work at this Level The student correctly determines the probability that the defective monitor was assigned to Sally is . When determining the probability that the defective monitor was assigned to a boy at Hub A, the studentÂ says the probability is:
 Three out of six (because there are three boys out of six students at HubÂ A).
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 50% (because half of the students are boys).
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 Six out of 24 (because there are six students at Hub A).
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Questions Eliciting Thinking How did you determine your probabilities?
What is question two asking? How many favorable outcomes are there? In other words, how many boys are there at Hub A? How many possible outcomes are there? Can you use that information to determine the probability? 
Instructional Implications Review the concept that the probability of an event is the number of outcomes favorable to that event compared to the total number of outcomes. Explain that since there are three boys at Hub A, then the number of favorable outcomes is three, and the total possible outcomes is still 24. Clarify that the question is not asking the probability that the defectiveÂ monitorÂ is assigned to one particular boy , or to a boy givenÂ the defective monitor is at Hub A . Ask the student to find the probabilities of other events related to the given scenario. For example, ask the student to find the probability that the defectiveÂ monitorÂ is assigned to:
 A boy.
 A girl.
 A student at Hub C.
 A student whose name is written with more than four letters.
 A student other than Sally.

Got It 
Misconception/Error The student provides complete and correct responses to all components of the task. 
Examples of Student Work at this Level The student determines the correct probability of each event:
 P(Sally) = or equivalent (because there is one student named Sally out of 24 possible students who might be assigned the defective monitor).
 P(boy at Hub A) = or equivalent (because there are three boys at Hub A out of 24 possible students who might be assigned the defective monitor).Â
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Questions Eliciting Thinking How likely is it for Sally to be assigned the defective monitor?
How likely is if for any student at Hub C to be assigned the defective monitor? 
Instructional Implications Ask the student to find the probabilities of other events related to the given scenario. For example, ask the student to find the probability that the defectiveÂ monitorÂ is assigned to:
 A boy.
 A girl.
 A student at Hub C.
 A student whose name is written with more than four letters.
 A student other than Sally.
 A boy, given that it is at Hub C.
Consider using MFAS tasks Number Cube and/or Marble Probability (7.SP.3.7) to further assess the student.
