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
a.   Ms. Needham made a lasagna for dinner with her family. She cut the lasagna into 12 pieces. Her family ate 4 pieces of lasagna the night that she made it. The next day, they ate 3 more pieces. What fraction of the lasagna did Ms. Needham’s family eat altogether?
b.   Ms. Roll is stringing beads to make a 16-inch necklace. At the end of the first night of working on it, she has 5 inches of beads strung. At the end of the second night of working on it, she has another 7 inches of beads strung. What fraction of the necklace has Ms. Roll completed?
Problem 2
Solve. Show your work with an area model or a number line.
a.
$$\frac{7}{8}+\frac{6}{8}$$
b.
$$\frac{13}{12}+\frac{5}{12}$$
Problem 3
Solve. Show or explain your work.
a.
$${5{1\over8}+{5\over8}}$$
b.
$${9{11\over12}+{11\over12}}$$
c.
$${3{4\over17}+4{8\over17}}$$
d.
$${2{11\over15}+2{13\over15}}$$


aligns: no