Given:
Initial price of the stock=$43.85
Change for the first two days=+$2.70
Change for next two days=-$1.10
Last day=-$4.45
The objective is to find the price at the last day.
Let's take the price at final day as <em>x</em>.

Hence, the price of the stock at the last day is $42.6
Keep the denominators the same and subtract the numerators. So for example in your example:
7/8 - 3/8
Leave the 8 alone. Subtract 3 from 7.
7 - 3 = 4
So answer is:
4/8
Sometimes they may have to simplify the answer, and in this case, 4/8 could be simplified to 1/2
Answer:
Just under 62 inches.
Step by Step:
4.9×2×Pi= 30.7876080052. x2= 61.5752160104
Look at some shorter periods of time to decide whether their reasonable. Do that by simplifying the fraction. . . . . 40,000 pounds / 80 years = 4,000 pounds / 8 years = 2,000 pounds (1 ton) / 4 years = 1,000 pounds / 2 years (have you decided yet ? Well, simplify it some more) 1,000 pounds / 2 years = 500 pounds per year = almost 1 and 1/2 pounds of bread every day of your life. NOW what do you think ? Make sense ?