Operations with Numbers
"Operations" means things like add, subtract, multiply, divide, squaring, etc. Here are some examples:
8x14
12÷3 5+3+98 
Does the order of operations matter?
Why don't you take a look at an example and decide for yourself. The example is: 3+4x2=

Order of Operations
In the above example, two students get different answer when solving the same problem. Imagine how chaotic it would be if you were not assured of getting a consistent answer when solving math problems. So it's clear that the order of operations in math does matter. The "Order of Operations" is a set of rules that mathematicians have agreed to follow in order to avoid confusion. You can use a simple acronym to remember the order:
So in the example above, Student 2 got the right answer because multiplication is done before addition: 3+4x2=11

The following provides more information on the details behind PEMDAS. First you do anything in parenthesis, then any exponents, followed by multiplication and division, and finally addition and subtraction. Notice multiplication and division are at the same "level" of importance. In that case you would work the problem from left to right (NOT multiplication before division). The same is true for addition and subtraction.

Video Tutorials
Here are some videos that teach you about the Order of Operations. The Khan Academy videos (black background) starts with an introduction. Each subsequent video shows different examples.





This is an excellent video. The instructor shows 7 examples that illustrate different aspects of Order of Operations. The last example involving fractions may be too advanced and you can skip it.

Other Tutorials
Here are some other sites that explain how the Order of Operations work:
@HomeTutor  This provides a stepbystep explanation and online exercises to check for understanding.
Math is Fun  provides examples of the right and wrong way to do Order of Operations
Math Goodies  examples and online exercises. It does not include "exponentials"
Online Activities
Here are some fun ways to practice your Order of Operations knowledge:
This game tests your knowledge of the order of operations without doing any arithmetic.

This game tests your knowledge of the order of operations without doing any arithmetic.

This game tests your knowledge of the order of operations including doing the arithmetic. It forces you to solve the problem one step at a time. This game can be played on the iPad.

Practice Worksheets
Use these for practice. Some of the sites allow you to print the questions. Others are online only. In either case, you should systematically work through the problems on paper and then double check to make sure your answers are correct.
Math Aids  Select the level of problem you'd like to practice. Answers are available to double check your work.
Dad's Worksheets  Select the level of problem you'd like to practice. Answers are available to double check your work.