standard_description: Apply properties of operations as strategies to add and subtract. (Students need not use formal terms for these properties.) Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)
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