SWBAT add or multiply and decompose fractions.

Using a simple cereal snack recipe, we learn what it truly means to decompose fractions through cooking.

10 minutes

My students need constant reinforcement in math fact fluency. Subtraction is still a weak area for my students. They can rattle off their multiplication facts, but when I ask what 11-5 is, they stumble. So today, we logged onto our iPad ap Timed Test and set it up for two subtraction tests.After those were complete, they needed to do two multiplication tests. I set them up individually for time and amount of problems in order to meet the needs of my students. I set the subtraction problems to 30 problems for most. This ap keeps record of the scores. Students stopped and compared their work from multiplication compared to subtraction. The subtraction scores were in the 60 % range on average. They were surprised at how low their subtraction scores were. We discussed the reasons why. In the discussion they came up with the idea that perhaps they just don't subtract enough! In order to master the standard for fluency in adding and subtracting, multiplying and dividing, I think my students are right! We just need to do it more! This is a great way because the ap can be set to fit their needs.

20 minutes

Materials: A box of Rice Chex, Cheerios, raisins, a bag of popcorn, pretzels and one bag of multi-flavored and colored marshmallows. A big bowl and spoon. Measuring cups.

Cooking for the Class Discovering How Division is Related to Decomposition

Using my SB file, we began our lesson whole class by looking at the recipe on the first page. I made up this snack recipe based on another granola type recipe and omitted any nuts because of allergies. The students were excited until a few of them saw the raisins in the ingredients. I took a moment to talk about what foods were healthy in our ingredients and what nutrients each had. We voted and the raisins stayed in!

I continued on with the lesson as I instructed them to take a picture of the recipe.Snapping the Recipe helps students see the recipe more easily when they start to manipulate the numbers and convert it to four times as much.

I gave them explicit direction for what to do in order to get the recipe converted correctly. I demonstrated how to do the first ingredient using a "think aloud." I talked to them using dialogue that let them hear my thinking out loud. This number turned out to be an improper fraction that converted to two wholes. We decided it was just easier to multiply 2x4. We concluded that 8 cups of rice Chex cereal would be added to our bowls. I told them to continue to write each ingredient and convert to the amount needed. They were instructed to use their notebooks to convert their recipe.Recipe

Everyone was done about the same time. I had planned on them working on their iPads in between waiting, but I didn't need to. They had finished with the exception of two. So, we moved on to talking about what we had learned through the process.

20 minutes

My students were so excited to cook! We took our ingredients to the science lab so that we could make a mess if we needed to without doing it in the classroom. We listed out our conversions on the board for each ingredient.

To support MP 5, I held up the measuring cups and asked which of the cups were the correct choice for measuring out 8 cups. They answered 1/4 of a cup. When I asked why they chose it, a few explained that it was the unit fraction in the original recipe. *Wow. This connection I didn't expect.*

Another student raised his hand and told us that we needed to use the largest cup. It would go faster. I explained that we need to use the largest cup because it would be more accurate. I demonstrated by using 1/4 of a cup after I filled up a one cup measure with M& M's. I had a student predict how many 1/4 cups were in the 1 cup measurement. She predicted 5. Others argued it would be 4 because 1/4 four times was one whole. A student scooped out the cup and sure enough there was more in the bottom. I asked why they thought that was. They decided we had spilled. I explained that it had to do with the volume of the M& M's and that the cup would have to be packed down tighter to be more accurate.

We experimented with different size cups by using them to decompose whole numbers. We counted the 1/4 cups twelve times.Decomposing with quarter cups shows a student using 1/4 cups to count.

When the lesson was done and all ingredients were stirred up we ate our snacks. The students thought they were great!