Using a recipe is a great real world application to review multiplicative comparisons and help students see that 1/4 of something is the same thing as dividing by 4. I decided to warm up on this because this light and fun activity would relax them. I chose a recipe from The Math Chef by Joan D'Amico and Karen Drummond to get my kids thinking about heart healthy recipes as we celebrate Heart Health Month.
We talked about how many students had eaten cooked carrots or baked apples before. Most had never had baked apples. I explained how you can easily bake a whole apple and what a delicious treat it is! One student asked me to share a written recipe; he wanted to try it out. We talked about the nutrients in carrots and apples and how they help our bodies grow and keep our teeth and organs healthy. A little chat like this sets the tone for being interested in the real world situation that would help master the standard regarding multiplicative comparisons.
I wrote down the recipe on the SB. I had photographed it on my iPad and showed it up on the SB so that students could easily see the original recipe.
Their task was to figure out what 1/4 of this recipe would call for.
4 medium apples
4 TBS of firmly packed brown sugar
1/2 tsp nutmeg
8 TBS butter ( the recipe calls for margerine) crossed it off and wrote butter.
I quickly asked about what 1/4 OF something meant. I have posted their vocabulary around the room to remind them of which vocabulary meant to divide and which meant to multiply. I wondered if they would be able to figure out 1/4 of 1/2. They hadn't been exposed to that concept yet, but I like to challenge their thinking with everything. Mastery of this wasn't important, just the immersion in critical thinking and problem solving. It was a risk...and I encourage risks!
Someone said " Multiplying by 1/4....of means multiply. That's the same as dividing something into 4 pieces."
Their completed work was their ticket to getting their quiz. When they were done they had to show me their work. Some of my students drew out the 1/4 of 1/2 and I was thrilled to see the thinking. 1/4 of 1/2 Others could just explain that they multiplied the fractions because of the word "of".Apple Carrot Recipe
Students who could not draw or figure out what 1/4 of 1/2 was used the manipulatives on the board as I helped them achieve the concept. I leave these magnetic fractions up all year. They get used a lot! Magnetic Fractions.
I wrote this quiz to measure how well students can divide using the box method. It is a straightforward quiz for the first 4. Then, I thought it was important to measure what we had learned through the lessons "The Sieve of Eratosthenes" and "The Bubble Wrap" lesson.
Preparing them for Smarter Balance Test or PARC tests requires that they write, write, write! Every chance I get, students need to write and explain their thinking. The last problem makes them show equations and explain their understanding of the inverse.
I encourage and write in directions that I expect complete sentences. As teachers of mathematics, I believe that they need to be able to write clearly and exceptionally about math. That means that language skills need to be at their best. I included a word bank to help the light bulb go on in their heads to use math vocabulary in their explanation. On the test, I will expect that they remember the words without a word bank and just a prompt to be sure to use appropriate math terms.