Can you recommend a site that will show how to divide whole numbers by fractions or give me an example.

When you divide by a fraction, you must turn the fraction upside down and then multiply.

10 / (1/5)
(10/1) * (5/1) = 50/1 = 50

http://www.mathwizz.com/fractions/help/help12.htm

adding and sudtracting frations with unlike denominators