standard_description: Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example, 2/3 + 5/4 = 8/12 + 15/12 = 23/12. (In general, a/b + c/d = (ad + bc)/bd.)
problem_activity: Problem 1
a.   Kyle has 6 Skittles.
$${{1\over3}}$$
of them are red. How many of Kyle's Skittles are red?
b.   Samantha also has 6 Skittles.
$${{2\over3}}$$
of them are red. How many of Samantha’s Skittles are red?
Problem 2
a.   Find the value of each of the following.
|  i.                                 $$\frac{1}{3}$$                                of 9   | ii.                                 $$\frac{2}{3}$$                                of 9  |
|-------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------|
| iii.                                 $$\frac{1}{5}$$                                of 10 | iv.                                 $$\frac{4}{5}$$                                of 10 |
|  v.                                 $$\frac{1}{4}$$                                of 12  | vi.                                 $$\frac{2}{4}$$                                of 12 |
b.   What do you notice about the solutions to the computations in the leftmost column of the table? What do you wonder?
c.   What do you notice about the solutions in each row of the table? What do you wonder?
Problem 3
a.   Mrs. Pham has 8 apples. She wants to give
$${{3\over4}}$$
of the apples to her students. How many apples will her students get?
b.   In a class of 24 students,
$${{5\over6}}$$
of them are boys. How many boys are in the class?


aligns: no