How much is a million?

A million is equal to

1,000,000 = 106

In the SI system of units, when we have 106 of something there is a special prefix we use in order to say 106 quickly. We put the word

mega

in front of the something we have 106 of. Often mega is shortened to just the letter

M

Think of the computer you are using to look at this CD-ROM. The memory, diskspace and size of files on your computer is measured in bytes. This word is often shortened to just `b' when we are writing down the number of bytes something has. So if your computer has a 15 Mb file on it then it contains

15 Mb = 15 x 106 b =
15,000,000 bytes

of information. The SI system of units has a lot more prefixes in it to tell you the size of something.