These units of measure are used in many different areas, not just electronics. Note that in science and engineering, though, an upper case 'M' represents a million and a lower case 'm' represents a millionth.

Number Name Scientific Notation Prefix Abbreviation
1,000,000,000 1 billion 109 giga G
1,000,000 1 million 106 mega M
1,000 1 thousand 103 kilo k
100 1 hundred 102
10 ten 101
1 1 100
0.1 tenth 10–1
0.01 hundredth 10–2
0.001 thousandth 10–3 milli m
0.000001 millionth 10–6 micro µ
0.000000001 billionth 10–9 nano n
0.000000000001 trillionth 10–12 pico p