SI prefixes
1000m 10n Prefix Symbol Short scale Long scale
Base 2
Binary Base 10
Decimal
10008 1024 yotta- Y Septillion Quadrillion 280 1,208,925,819,614,629,174,706,176 1 000 000 000 000 000 000 000 000
10007 1021 zetta- Z Sextillion Trilliard 270 1,180,591,620,717,411,303,424 1 000 000 000 000 000 000 000
10006 1018 exa- E Quintillion Trillion 260 1,152,921,504,606,846,976 1 000 000 000 000 000 000
10005 1015 peta- P Quadrillion Billiard 250 1,125,899,906,842,624 1 000 000 000 000 000
10004 1012 tera- T Trillion Billion 240 1,099,511,627,776 1 000 000 000 000
10003 109 giga- G Billion Milliard 230 1,073,741,824 1 000 000 000
10002 106 mega- M Million 220 1,048,576 1 000 000
10001 103 kilo- k Thousand
210
1,024
 1 000
10002/3 102 hecto- h Hundred
 
   100
10001/3 101 deca- da Ten
 
 
10
10000 100 (none) (none) One
20
1
 1
1000−1/3 10−1 deci- d Tenth     0.1
1000−2/3 10−2 centi- c Hundredth     0.01
1000−1 10−3 milli- m Thousandth     0.001
1000−2 10−6 micro- µ Millionth     0.000 001
1000−3 10−9 nano- n Billionth Milliardth     0.000 000 001
1000−4 10−12 pico- p Trillionth Billionth     0.000 000 000 001
1000−5 10−15 femto- f Quadrillionth Billiardth     0.000 000 000 000 001
1000−6 10−18 atto- a Quintillionth Trillionth     0.000 000 000 000 000 001
1000−7 10−21 zepto- z Sextillionth Trilliardth     0.000 000 000 000 000 000 001
1000−8 10−24 yocto- y Septillionth Quadrillionth     0.000 000 000 000 000 000 000 001

 

Short scale- It refers to a system of numeric names in which every new term greater than million is 1,000 times the previous term:
"billion" means "a thousand millions" (109), "trillion" means "a thousand billions" (1012), and so on.
Long scale- It refers to a system of numeric names in which every new term greater than million is 1,000,000 times the previous term:
"billion" means "a million millions" (1012), "trillion" means "a million billions" (1018), and so on.
Until 1974 the UK used the long scale, it now officially uses the short scale