As other answerers have pointed out, the first six lines are from Shakespeare's sonnets, numbered 3, 60, 5, 5, 5, and 12. However, I believe that they have been misinterpreting the mathematics.
The point must come soon after when thou viewest,
A decimal point must be placed somewhere near the start of those numbers. With this information alone we can't do anything yet, but supposedly it implies that those numbers must be strung together to create 36055512, and then a decimal point inserted somewhere.
When squareth it that debt all owe the hour,
Then the number obtained by placing that decimal point must be squared, and then the difference from 60 taken of the result. If we square 3.6055512, the result is 12.99999945582144. The difference from this number and 60 is 47.00000054417856.
And then thine sharpened figure shall be rounded.
This simply means "round your result to the nearest integer". This gives us a result of 47.