Proportionality assessment

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Objective

SWBAT test for proportionality using ratio, percent, and a graph as well as to explain their conclusion.

Big Idea

Students need to explain how all three forms of mathematical evidence show proportionality.

Intro & Rationale

This is a performance task which requires students to figure out which populations of lady bugs are proportional and then to support their conclusion with three forms of mathematical evidence and to explain their reasoning. Students have access to a rubric during their test and have practiced with it in previous lessons (Assessment Rehearsal & Critiquing the assessment). Students may need some extra encouragement to keep at it and the teachers role is to redirect them to the rubric if necessary. The rubric doesn't help them with the math or how to make their decision, but it does give some organizational suggestions and outlines the explanation guidelines. The rubric is a really nice support to help them persevere.

Warm up

10 minutes

After revising their first assessment from an earlier lesson (assessment rehearsal) using a rubric I ask students to briefly discuss with their math family group and then with the whole class what changes they made to their test. I expect much of the discussion to focus on organization and explanation. The purpose of this discussion is to keep those changes in mind as they are working on today's assessment. I tell students they may use the rubric during the test because I want them to do their best.

Assessment

39 minutes

Normally I have them turn in their tests when they are done and have a homework assignment for them to do for the remainder of the period. Today I tell them I don't want anyone turning in their test before the bell. I tell them it is because if I (their math mommy) look at them I might cry from being so proud of them and I don't want to distract them with my happy tears. Although this is possible, the real reason is that I want them to go back over their work and give themselves a chance to revise it.

As I circulate during the test I may give some pointers by bringing their attention to a certain part of the rubric. I am specifically looking for labeling, lines on the graph, and complete explanations. Some students just need some positive reinforcement as they work. They may ask questions like  "is this okay?", "does this make sense?" to which I respond "what math could you do to double check", "could you use the graph to double check?", "did you find the same thing with the ratios?", "does it explain why?