This week, students worked with multiple representations for modeling the multiplication of fractions. We used arrays/grids, pattern blocks, circles, timelines, etc. We also began working with several word problems requiring multiplication of mixed numbers. Models for these types of problems are significantly more challenging, and we will continue to work with more word problems next week.
Fifth graders took the first nine weeks benchmark test this week, and the results were very good! Most students only answered a few questions incorrectly, and they understood their mistakes when we went over the test together. We have also continued to practice adding, subtracting, and multiplying decimals and adding/subtracting mixed numbers and fractions this week. Our focus has been on choosing the correct operation in word problems and on working accurately.
Ms. Lewis’s class also worked on a lesson this week for which they attempted to build the longest possible cantilever using a limited number of popsicle sticks and tape. Some groups tried several different designs to see which one worked the best. This week, fifth graders reviewed adding and subtracting with fractions and mixed numbers. They practiced subtraction with and without regrouping, and they learned how to model the multiplication of decimals using hundreds grids. Most importantly, they discovered that multiplying a decimal less than one by another decimal less than one results in a product smaller than the factors. This was a big surprise for many students because multiplication of whole numbers has always resulted in a larger product. We also discussed the impracticality of modeling hundredths by hundredths since they would need a ten thousandths grid. Therefore, we reviewed and practiced the traditional algorithm for multiplying decimals when a model is not necessary.
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Mrs. GregoryMrs. Gregory has been a teacher for 25 years. She lives in Montpelier with her husband, two daughters, and two dogs. Archives
December 2016
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