Magnification
When you see a number on a scope followed by an "X" such as the "3x-9x" pictured below those numbers refer to the magnification power of the scope. This particular scope for example has a magnification range between 3 and 9 times normal eyesight meaning you can set the scope to see anywhere between 3 to 9 times the distance than you can see with the naked eye.
Adjustment knobs
On the left side of your scope, in the middle, will be a cap that screws off. Under this cap you will see numbers and click marks. This is the horizontal or left and right adjustment. When you're sighting in your gun, turn this nob one click at a time left or right, depending on which direction your shot is off center.
To the right of the horizontal adjustment knob will be the vertical adjustment nob. This adjusts your scope up or down.
Magnification Control
The series of numbers just above your eyepiece is the magnification adjustment knobs. This allows you to choose how much magnification you want to use. The numbers will generally be from 2 and up. Two means the view with the scope appears twice as close. Three means the view appears three times closer than normal site and so on.
Model and serial numbers
Other numbers you might find on your scope include a make and model number and a serial number. A make and model number will be between 5 and 8 numerals long and a serial number will have between 10 and 20 numerals in a series. These numbers help the manufacturer to identify your scope.
Dimensions
Some scopes will also have the scope size stamped on the shaft. This is the dimensions of the scope. If your scope measures 1.5 inches by 12 inches, you will see "DEM1.5/2X12" stamped on the bottom of the shaft.