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.
I have several web pages intended for students ; this seems to be the most popular one. FONTS FINALLY REPAIRED November 2009. Browser adjustments: This web page uses sub scripts, super scripts, and unicode symbols . The latter may display incorrectly on your computer if you are using an old browser and/or an old operating system. Note to teachers (and anyone else who is interested): Feel free to link to this page ( around 500 people have done so ), tell your students about this page, or copy (with appropriate citation) parts or all of this page. You can do those things without writing to me.
Cheat Sheets and Tables Here is list of cheat sheets and tables that I've written. Most of these are pdf files and so you will need the Adobe Viewer to view them. You can download the latest version here . Algebra Cheat Sheet - [ pdf ] - This is as many common algebra facts, properties, formulas, and functions that I could think of.