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. Common Errors in College Math. 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 subscripts, superscripts, 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. This web page describes the errors that I have seen most frequently in undergraduate mathematics, the likely causes of those errors, and their remedies. (There is some overlap among these topics, so I recommend reading the whole page.) ...
Errors in Communication Some teachers are hostile to questions. A variant of teacher hostility is teacher arrogance. Unclear wording. . ∫ (5x4+2)dx 3 ∫ (5x4+7)dx 3x5+7x+C. Pauls Online Math Notes. 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. There is also a page of common algebra errors included. The Secret to Teaching Math Facts: Number Bonds. Below you will see why I think teaching math basics with number bonds is the best way for your homeschoolers to learn math.
Over our last four years of homeschooling, I have used several different math curricula. Some I liked better the others, but they all had their own strengths and weaknesses. One of the strengths of one particular curriculum we use, Singapore Math, is their method of teaching basic math facts. Instead of teaching fact families by rote, Singapore illustrates fact families using number bonds. Now, I realize this is just my unprofessional opinion, but as a self-professed math geek, I truly believe number bonds are (likely) the best ways to teach math facts. Why? They're simple. How Number Bonds Work If you're not familiar with what number bonds are, allow me to illustrate.
As in the example for addition on the left, the student is taught to recognize that the number 7 is made of 3 and 4. Number Bond Flashcards Teaching Algebraic Thinking. Free Graph Paper Generator: Graphpaper Printing Tool.