Sunday, October 26, 2008

How to Solve Equations
Equation: Two numbers or expressions that have the same value
Variable: A letter that represents a number that can very
An equation is like a balance that you have to keep balanced. Whatever you do to one side of the equals sign, you have to do to the other.When you solve an equation, the main thing you are trying to do is get the variable by itself.
example:
5+x=30
-5 -5
x=25
You probably have no idea what the example means, so I'll talk you through it. the problem was
5+x=30. We are trying to get the x by itself, so we don't want the 5. Plus 5 minus 5 equals 0, so you subtract 5 from both sides(whatever you do to one side you have to do to the other). After you subtract 5 from 30, you fave the answer- x=25. I'll do another example and hopefully this one will make more sense.
example:23-n=13
+23 +23
n=36
You're probably wondering why it's +23 instead of -23 like before. The reason is that you always do the opposite operation from what is in the equation. Minus 23 plus 23 equals 0. 13+23 equals 36 so n=36.
Checks
A check is exactly what it's name suggests- it checks your answer to an equation. All you have to do in a check is plug the answer into the equation and solve it.
example:23-n=13
23-36=13
13=13
n=36
As you can see, I checked the last example and it turned out to be right.
For more help, click here

Tuesday, October 7, 2008

Factor-
A number that divides evenly into another number
This might look scary at first, but don't worry! It will make sense soon. Lets start with something easy like 12. The factors of 12 are 1,2,3,4,6 and 12. Why aren't 5,7,8,9,10 or 11 factors of 12 you may ask. They are not factors of 12 because if you divide any one of them by 12, you will get a number with a decimal point. Lets try something harder, factors of 64. 2 and 32 are factors of 64 because if you multiply them together you will gt 64. Other factors of 64 are 4, 16, and 8.
Greatest Common Factor
Greatest Common Factor (G.C.F.) is the largest number that is a factor for two different numbers.
Example=80-1,80,2,40,4,20,5,16,8,10
36-1,36,2,13,3,12,4,9
In this case, the G.C.F. would be 4 because that is the highest factor that goes into both 80 and 36. A way you would use G.C.F. in real life is when simplifying fractions.
Prime numbers
Prime numbers are numbers with only 2 factors: 1 and itself. Some prime numbers are 2,3,5,7,11, and 13.
For more help with fractions, click here

Sunday, September 28, 2008

Exponents make big numbers a lot easier to write. The exponent tells you how many times to multiply the other number.

Parts of an Exponent

23 this is an exponent. The number on the left (the 2) is the base number, this tells you what to multiply by. The number on the right (the 3) is the exponent, this tells you how many times to multiply the base.
Two ways to solve an Exponent
Example #1-26=64 This means two to the sixth power equals sixty four or 2 x 2 x 2 x 2 x 2 x 2=64
not 2 x 6

Example#2:44 or four to the fourth power. This is how to solve it- 4 x 4=16 and 4 x 4=16 then 16 x 16=256.

For more help with exponents go to http://www.purplemath.com/modules/exponent3.htm