Unit Assessment of Addition and Subtraction of Fractions With Like Denominators

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SWBAT prove they understand how to add and subtract fractions with like denominators.

Big Idea

This test assesses a variety of problem solving skills involving addition and subtraction of fractions with like denominators, using decomposition, and fractional models to prove their work.

Warm Up: Complete the Whole

10 minutes

I was inspired to figure out a game that would force students to mentally complete a whole and use mixed numbers to help with number sense and fluency.

We formed a circle around the classroom. The object of this game is to find the remaining fraction that makes the whole. This mental subtraction/addition activity strengthens their mindset to prepare for the test today.

I stood in the middle of the circle and explained that I would be giving a fraction or a mixed number and they needed to complete the next whole by naming the fraction that I would need to add to get to the next whole. The first student who raises their hand with the answer may say the answer.

I started by saying 1 2/8. A student's hand shot up and she answered 6/8. She took my place in the circle and said 22 4/5. She called on a boy who answered 1/5. He took her place and said 10 10/12, and the process went on and on.

At ten minutes, most of my students had their turn in the circle. I watched and coached one student who has difficulty with mental math, but she really made some good strides with subtraction.

This game also reinforces subtraction fluency that my class is weak in. I loved it!

The Test

45 minutes

Assessment Addition and Subtraction of Fractions With Like Denominators

I designed this exam to assess the standard fully by using unit fractions, decomposition and word problems. Students are expected to show all work and show me their thinking through drawings. They must show that they can decompose fractions in more than one way. The expectations that are listed above are the standards expected to be mastered. I worded it with "I can"....so that it was personalized and helped them understand what was on the test.

I passed the exam out and it took a full 45 minutes for some students to complete. They tended to not read all of the directions on their last quiz, forgetting to prove their thinking using drawings. So, I had them highlight the directions as I read them aloud before the exam began, to make sure they completely understood. I also emphasized that I didn't want to see comparison drawings and showed them the difference one more time on the white board.