Benford's law

Benford's law, also referred as first digit law, is a principle that in any large random real-life sets of numerical data, around 30% numbers begin with 1, around 18 percent begin wit 2, and so on, very small data begins with leading digit 9.  It is a frequency distribution law of nature.

Simon Newcomb, american astronomer, noticed in 1881 that first few pages of logarithm books are used more.  Frank Benford, physicist, paid attention to it in 1938. He collected data from 20 different domains like surface areas of rivers, sizes of populations, physical constants and numbers from a reader's digest magazine.

References
Wikipedia Benford's law
Wolfram Mathworld page

Occam's razor

Occam's razor is a guiding principle to verify a hypothesis, to propose a theory, to solve a problem or to deduce logical conclusions. Other things being equal, simpler explanations are better than the complex ones.  More things should not be used than are necessary. It is a law of briefness that says that it is not worth it to do with more what is done with less.

Ockham was a town in England. William of Ockham was an early 15th century English theologian and philosopher. Jis original words are "plurality must never be posited without necessity". Razor was referred to shaving away unneeded assumptions to prove a hypothesis. It is a tool to encourage parsimony in argument or simplicity in logic. It says that simplest explanation is usually the right one.

It is used in many number of fields in science, medicine, logic, mathematics, philosophy, theology and law. It can also be used in context of simple things and observations in every day life. It helps in reasoning to slice through the problem or situation. If you find a fallen tree, most possible claim to verify first is that some wind would have blown it down rather than some meteorite hit it which requires several other rare things to happen.

References
Wikipedia Occam's razor
HowStuffWorks Occam's razor