A scaling problem Audrey has designed a banner that is 4 inc

A scaling problem: Audrey has designed a banner that is 4 inches wide and 20 inches long. Now Audrey wants to make a scaled up version of the banner. The sealed up banner. The scaled up banner will be 12 inches wide. How long should the scaled up banner be? Determine the answer to the scaling problem in two ways other than by setting up a proportion case, explain why the method makes sense as if you were explaining it to a student who understands about multiplication and division (but who does not know about setting up proportions).

Solution

(1.) Multiplication method-----

Before, wide = 4 inches long = 20 inches

After wide = 12 inches = 3*4 inches

wide = 3*wide in before scaled up

So same as long = 3*long in before scaled up

long = 3*20 inches

long = 60 inches

(2.) Division method-------

Before, wide = 4 inches long = 20 inches

After, wide after scaled up = 12 inches

wide after scaled up / 3 = 4 inches

wide after scaled up / 3 = wide before scaled up

So, same as long after scaled up / 3 = long before scaled up

  long after scaled up = 3*20 = 60 inches