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# Numbers, Massive

Many questions about computers are answered with numbers that have the prefixes "kilo," "mega," "giga," and even "tera" in their name. An understanding of these prefixes, and the massive numbers they represent, will help consumers navigate their way through the world of computers and other technologies.

## Understanding Massive Numbers

Massive numbers are part of the metric system. The French Academy of Science introduced the idea for this system in 1790. It was originally created to measure length, mass, volume, temperature, and time. In 1960, countries that used the metric system agreed on rules for its use. It is now called "SI," which stands for Système International d'Unités French for "International System of Units."

In the SI system, a basic unit is determined. Other units are created by multiplying the basic unit by powers of ten. In the field of computers, for example, the basic unit of memory is the byte . Larger amounts of computer memory are designated by combining the "byte" unit with the prefixes kilo-, mega-, giga-, and so on.

All of the prefixes for numbers greater than the basic unit come from Greek or Latin. The list below shows the prefixes, their multiple, the power of ten, and their root. Prefixes for massive numbers make it easy to compare them.

 Prefix Multiple Power of Ten Root yotta septillion 1024 Greek: octo—"eight" zetta sextillion 1021 Latin: septem—"seven" exa quintillion 1018 Greek: hex—"six" peta quadrillion 1015 Greek:: penta—"five" tera trillion 1012 Greek: teras—"monster" giga billion 109 Greek: gigas—"giant" mega million 106 Greek: megas—"great" kilo thousand 103 Greek: chilioi—"thousand" hecto hundred 102 Greek: hekaton—"hundred" deka or deca ten 101 Greek: deka—"ten"

## Using Massive Numbers

A computer stores information on its hard drive. Space on a personal computer (PC) hard drive, as well as computer memory, is measured in bytes. In the early days of personal computers, hard drives were measured in megabytes of space, and memory was measured in kilobytes. Eventually, the one-gigabyte hard drive was developed. As software programs for computers became more complicated, the files created took up more space on a computer's hard drive. Therefore, increasingly larger hard drives became necessary to store all of the information. PCs sold in 2000 were available with 80 gigabytes.

Speed in computer microprocessors is measured in terms of frequency, or the number of computations completed per second. The metric unit of frequency is the hertz (Hz). A microprocessor with a speed of 1Hz can do one computation per second.

Imagine that a store is selling two different computers for the same price. One of them has a 500-megahertz microprocessor, and the other has a one-gigahertz microprocessor. Which computer is the better value?

Look first at the prefixes "mega-" and "giga-." "Mega" means million and "giga" means billion. Five hundred megahertz is equal to 500 million hertz and one gigahertz is equal to one billion hertz. It is apparent that the computer with the one-gigahertz microprocessor is a better value since one billion hertz is twice as many as 500 million hertz. This means the computer with the one-gigahertz microprocessor is twice as fast as the one with the 500-megahertz microprocessor.

In the early 1990s some of the fastest microprocessors were only 64-megahertz. The first one-gigahertz microprocessors became available in personal computers in 2000. Computers will continue to get faster and more powerful in the future. It is possible that the speed of microprocessors will eventually be measured in terahertz and petahertz.

It is also helpful to understand massive numbers when looking at Internet service providers. Most important to consider is the speed at which information can be downloaded. Speed, which is measured in bytes per second, tells you how fast you can receive information over the Internet. The speed at which information can be uploaded, or sent, is generally much slower with Internet connections because people spend more time downloading than uploading.

In 2000, several types of Internet connections were available to home Internet users. Dial-up connections, where the user dials a local phone number to access the Internet, are the slowest, capable of downloading a maximum of 56 Kbps (kilobytes per second). Cable modems that are constantly connected to the Internet when the computer is on are much faster, with the ability to download up to 5 Mbps (megabytes per second). Just as micro-processors have become increasingly faster, Internet connections too will only become faster in the future.

Kelly J. Martinson

## Bibliography

Murray, Katherine. Introduction to Personal Computers. Carmel, IN: Que Corporation, 1990.

## MASSIVE ABBREVIATIONS

Abbreviations such as K (kilo), M (mega), and G (giga) help simplify terms representing massive numbers. For example, a 5G hard drive means that the hard drive has 5 gigabytes of space. A 600M microprocessor operates at a speed of 600 megahertz.