Tuesday, October 28, 2014

Introducing Fractions in Fifth Grade

After tomorrow, my students will be on their Fall Break from school until November 5th! We just finished Chapter 3 in math and I didn't want to start the next one with so many days off coming up. So instead, I did an mini-Investigations lesson. 

I asked students the following question:

James came home from school to find 3 fresh brownies. He had 3 friends with him. The 4 friends decided to share the brownies equally. How much of each whole brownie did each of them get to eat?

I broke the students up into small groups and gave them chart paper and markers. I told students that it was their job to not only find the answer, but to also be able to explain how they know that their answers are correct.

It turned out really well! I was happy that they all did not come up with the same strategies and there was great conversation around fractions, division and equal parts! 

Here is what they came up with:

This group decided to draw the three brownies, then split two in half to divide among all 4 boys (each getting half a brownie). They took the final brownie and broke it up into 4 equal parts and gave each piece to the boys. They then added 1/2 plus 1/4 (mentally) to say that each boy ate 3/4 of a brownie. 

This group did something similar. They drew out the three brownies and then broke each brownie into four parts so that they could divide the pieces equally among the four boys. There was great conversation around what the final answer would be to the question: How much of each brownie did everyone eat? At first, the group answered 1/4, but after discussing it with the rest of the class, they realized they had to add up each of the fourths that the boys ate. 

This group drew the three brownies, broke them up into fourths then distributed to each boy. 

This group also drew the three brownies and then split them into fourths. They said they chose fourths because they knew that 12 can be divided evenly by 4. 

I love Investigations lessons because it allows students to learn from each other. It was great to watch them work together in a group and then explain their findings and rationale with the rest of the class. Great way to introduce fractions and get a sense of background knowledge of each student!

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