standard_description: Interpret multiplication as scaling (resizing), by:
- Explaining why multiplying a given number by a fraction greater than 1 results in a product greater than the given number (recognizing multiplication by whole numbers greater than 1 as a familiar case); explaining why multiplying a given number by a fraction less than 1 results in a product smaller than the given number; and relating the principle of fraction equivalence a/b = (n×a)/(n×b) to the effect of multiplying a/b by 1.
- Comparing the size of a product to the size of one factor on the basis of the size of the other factor, without performing the indicated multiplication.
problem_activity: Problem 1
There are a few more ingredients in Lin’s family recipe for cookies, listed below. Write an addition equation and a multiplication equation to show how she can use the
$$\frac14$$
-cup measure to measure the amount of each ingredient below.
a.
$$\frac94$$
cups chocolate chips
b.
$$2\frac34$$
cup flour
Problem 2
Decompose each of the following fractions as a sum of unit fractions, a multiple of a unit fraction, and a sum of non-unit fractions.
a.
$${{8\over2}}$$
b.
$$3\frac{1}{4}$$
c.
$${{12\over5}}$$
Problem 3
Compose each of the following expressions.
a.
$${{1\over3}+{1\over3}+{1\over3}+{1\over3}+{1\over3}+{1\over3}}$$
b.
$${{3\over5}+{2\over5}+{6\over5}}$$
c.
$$12\times\frac{1}{4}$$
d.
$$9\times\frac{1}{2}$$


aligns: no