Subtract fractions from fractions less than 2 with unlike denominators.
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For some problems in this lesson, students may use a computation-specific strategy. For example, students might think of a computation as an unknown-addend problem and use an addition strategy to solve (including the simplifying strategy of making a whole, e.g., to solve $$1\frac{3}{5}-\frac{7}{8}=1\frac{24}{40}-\frac{35}{40}$$, a student might add $$\frac{35}{40}+\frac{5}{40}=1$$ and $$1+\frac{24}{40}=1\frac{24}{40}$$, so the difference is $$\frac{5}{40}+\frac{24}{40}=\frac{29}{40}$$). Students might also use a simplifying strategy like going down over a whole (e.g., $$1\frac{24}{40}-\frac{24}{40}-\frac{11}{40}=1-\frac{11}{40}=\frac{29}{40}$$). Discussing various strategies and their advantages and disadvantages “provide opportunities for students to compare approaches and justify steps in their computations (MP.3)” (NF Progression, p. 13).
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a. $$1\frac{2}{3}-\frac{1}{2}$$
b. $$1\frac{1}{2}-\frac{2}{3}$$
$${1{4\over5}-{5\over6}}$$
a. $$1\frac{3}{5}-\frac{7}{8}$$
b. $$1\frac{2}{3}-\frac{5}{6}$$
c. $$1\frac{5}{8}-\frac{5}{12}$$
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Solve. Show or explain your work.
$${1{1\over6}-{1\over4}}$$
Solve. Show or explain your work.
Tara baked $$1\frac{1}{2}$$ dozen cookies. She sold $$\frac{2}{3}$$ dozen of the cookies she made. How many dozens of cookies does Tara have remaining?
From EngageNY.org of the New York State Education Department. New York State Testing Program Grade 5 Common Core Mathematics Test Released Questions June 2017. Internet. Available from https://www.engageny.org/resource/released-2017-3-8-ela-and-mathematics-state-test-questions/file/150271; accessed Dec. 5, 2017, 3:55 p.m..
Modified by The Match Foundation, Inc.?