Anchor paper 328

Overall Achievement Level:

expert

Student Number:

Anchor Papers:

Problem Solving

expert

Problem Solving Rationale

The student's strategy of making a diagram to show the 10 crackers, crossing out the five eaten by Alexa and also providing a subtraction equation works to solve this task. The student's answer, "5," is correct. The student uses a different strategy of diagramming sets of crackers to verify that their answer is correct.

Reasoning and Proof

expert

Reasoning Proof Rationale

The student demonstrates correct reasoning of the underlying concepts of the task. The student diagrams the correct number of crackers and subtracts out five crackers. The student also brings the understanding of fair share/equal as well as one-half. The student uses equal sets of five crackers to verify that their answer is correct.

Communication Level

expert

Communication Rationale

The student correctly uses the mathematical terms diagram, key, equal, one-half, sets.

Connections Level

expert

Connections RationaleAnchor paper 328

The student makes the mathematically relevant Practitioner observations, "It is equal and it is a fair share." The student makes the Expert connection of bringing the concept of one-half to their solution. The student states, "I know five is one-half of ten like three is one-half of six." The student verifies their answer by diagramming a set of five crackers on a plate and a set of five crackers that Alexa ate. The student states, "One set of five and one set of five is ten crackers so five is right."

Representation

expert

Representation Rationale

The student's diagrams are appropriate to the task and accurate. A key defines the crackers and the scribing adds additional support to each diagram. The student creates the second diagram to verify that their answer is correct.