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
Geraldo is plotting points on the following coordinate plane.
[IMG]
Geraldo needs to plot the following four points:
(0.8, 12)
(1.6, 18)
(1, 30)
(2, 3)
Can he plot all of his points on the provided coordinate plane? How do you know?
What would be a point that he couldn't fit on the coordinate plane above? How do you know?
Problem 2
Determine the correct scale for the coordinate grid below so that all of the following points can be shown on it:
(12, 4)
(4,
$${1\over2}$$
)
(6,
$$3{1\over2}$$
)
(12,
$$2{1\over2}$$
)
(17, 4)
(16,
$$4{1\over4}$$
)
[IMG]


aligns: no