### dex

**(order-of-magnitude, decimal exponent)**
(a number or factor's log base 10)

**Dex** (for **decimal exponent**) is a unit specifying an
amount (e.g., a ratio) as the power of 10 that is
relatively near that amount.
Another widely used term for this is **order-of-magnitude**.
A difference is that a *dex* is sometimes quoted
as a fraction whereas an *order-of-magnitude*
is typically rounded to an integer.

This is the same as the log base 10 of the number.
For example, 100 could be described as 2 dex,
or two numbers that differ by a factor of
1000 could be said to differ by 3 dex.

Within physics and astrophysics, the term *dex* is sometimes used,
but *order-of-magnitude* is probably used more.

(*mathematics,terminology,unit*)
https://en.wikipedia.org/wiki/Scientific_notation#Dex

http://en.wiktionary.org/wiki/dex

**Referenced by:**

cosmic dust

dark energy

free-fall time

H-R diagram (HRD)

hyperfine structure

inflation

N-body problem

numerical analysis

planet formation

projected separation

stellar dynamics

task-based parallelism (TBP)

time standard

index