Nerd Paradise : Divisibility Rules for Arbitrary Divisors It's rather obvious when a number is divisible by 2 or 5, and some of you probably know how to tell if a number is divisible by 3, but it is possible to figure out the division 'rule' for any number. Here are the rules for 2 through 11... The last digit is divisible by 2. The sum of all the digits in the number is divisible by 3. The last 2 digits are divisible by 4. The last digit is 5 or 0. The number is both divisible by 2 and divisible by 3. Cut the number into 2 parts: the last digit and everything else before that. The last 3 digits are divisible by 8 The sum of all the digits in the number is divisible by 9. The last digit is a 0. Break the number into two parts (like you did for the division by 7 rule). Also there is a quick way for determining divisibility by 11 for 3-digit numbers: If the inner digit is larger than the two outer digits, then it is divisible by 11 if the inner digit is the sum of the two outer digits. Rules for all divisors ending in 1... User Comments: 9 Dividing By 12
Khan Academy - StumbleUpon axioms - StumbleUpon Contents Contents | rgb Home | Philosophy Home | Axioms | Other Books by rgb: | The Book of Lilith | Axioms is a work that explores the true nature of human knowledge, in particular the fundamental nature of deductive and inductive reasoning. The way out is to give up the idea of certain knowledge. Axioms by Robert G. Dedication This book is dedicated to the giants of mathematical and scientific philosophy upon whose backs it stands: Plato, Hume, Descartes, Gödel, Bayes, Shannon, Cantor, Cox, Jaynes, and many more, too many to count, actually. It is also dedicated to my philosophy professor and guru at Duke, George Roberts, who had an enormous impact on me as I pursued an ``invisible'' philosophy major at Duke to accompany my physics major (invisible because at the time Duke had no way of acknowledging the completion of a Bachelor of Science in one discipline and a Bachelor of Arts in another). No book is written in a vacuum. Notice Copyright Notice Copyright Robert G. Lulu Press www.lulu.com
Your Age on Other Worlds | Exploratorium - StumbleUpon Want to melt those years away? Travel to an outer planet! <div class="js-required"><hr> This Page requires a Javascript capable browser <hr></div> Fill in your birthdate below in the space indicated. The Days (And Years) Of Our Lives Looking at the numbers above, you'll immediately notice that you are different ages on the different planets. The earth is in motion. The top-like rotation of the earth on its axis is how we define the day. The revolution of the earth around the sun is how we define the year. We all learn in grade school that the planets move at differing rates around the sun. Why the huge differences in periods? Johannes Kepler Tycho Brahe Kepler briefly worked with the great Danish observational astronomer, Tycho Brahe. Here you see a planet in a very elliptical orbit. Kepler's third law is the one that interests us the most. Let's just solve for the period by taking the square root of both sides: The Gravity Of The Situation Isaac Newton ©2000 Ron Hipschman
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