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
Circle the expressions below that have a value of 2.
$${8+ (-6)}$$
$${6-8}$$
$${-{8-6}}$$
$${-8+(-6)}$$
$${8-6}$$
$${-6+8}$$
$${-8+6}$$
$${-6 - (-8)}$$
Problem 2
Rewrite each subtraction problem as an addition problem and each addition problem as a subtraction problem.
a.
$${-8-7}$$
b.
$${11+(-3)}$$
c.
$${20-(-2)}$$
d.
$${-4 + 16}$$


aligns: no