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
Act 1: Watch the following video –
The Big Pad (Act: 1)
a.   What do you notice? What do you wonder?
b.   What is the area, in square centimeters, of the big pad? Make an estimate.
Problem 2
Act 2: Use the following information to solve -
The small pad is a square with a length of
$$7\frac{3}{5}$$
cm.
The big pad is also a square and has a length equal to
$$3\frac{2}{3}$$
small pads.
Problem 3
Act 3: Reveal the answer -
The area of the big pad is
$$776\frac{124}{225}$$
square centimeters. Was your answer reasonable? Why or why not?
Problem 4
Act 4 (the sequel): Look at the following image of the dimensions mentioned on the big pad -
[IMG]
Do these dimensions result in the same area as what we computed in Anchor Task #3? Why or why not?


aligns: no