Deci-

Deci- (symbol d) is a decimal unit prefix in the metric system denoting a factor of one tenth. Proposed in 1793,^[1] and adopted in 1795, the prefix comes from the Latin decimus, meaning "tenth". Since 1960, the prefix is part of the International System of Units (SI).^[2]^[3]

A frequent use of the prefix is in the unit deciliter (dl), common in food recipes; many European homes have a deciliter measure for flour, water, etc. A common measure in engineering is the unit decibel for measuring ratios of power and root-power quantities, such as sound level and electrical amplification.

Example

The diameter of a compact disc is about 12 centimetres or 1.2 decimetres.^[4]

SI prefixes
v
t
e
Prefix		Base 10	Decimal	Adoption ^{[nb 1]}
Name	Symbol	Base 10	Decimal	Adoption ^{[nb 1]}
quetta	Q	10³⁰	1000000000000000000000000000000	2022^[5]
ronna	R	10²⁷	1000000000000000000000000000	2022^[5]
yotta	Y	10²⁴	1000000000000000000000000	1991
zetta	Z	10²¹	1000000000000000000000	1991
exa	E	10¹⁸	1000000000000000000	1975^[6]
peta	P	10¹⁵	1000000000000000	1975^[6]
tera	T	10¹²	1000000000000	1960
giga	G	10⁹	1000000000	1960
mega	M	10⁶	1000000	1873
kilo	k	10³	1000	1795
hecto	h	10²	100
deca	da	10¹	10
—	—	10⁰	1	—
deci	d	10⁻¹	0.1	1795
centi	c	10⁻²	0.01
milli	m	10⁻³	0.001
micro	μ	10⁻⁶	0.000001	1873
nano	n	10⁻⁹	0.000000001	1960
pico	p	10⁻¹²	0.000000000001	1960
femto	f	10⁻¹⁵	0.000000000000001	1964
atto	a	10⁻¹⁸	0.000000000000000001	1964
zepto	z	10⁻²¹	0.000000000000000000001	1991
yocto	y	10⁻²⁴	0.000000000000000000000001	1991
ronto	r	10⁻²⁷	0.000000000000000000000000001	2022^[5]
quecto	q	10⁻³⁰	0.000000000000000000000000000001	2022^[5]
Notes

References

[1]

[2]

[3]

[4]

[nb 1]

[5]

[6]