PlanetMath (more info)
 Math for the people, by the people. Sponsor PlanetMath
Encyclopedia | Requests | Forums | Docs | Wiki | Random | RSS  
Login
create new user
name:
pass:
forget your password?
Main Menu
Owner confidence rating: Very high Entry average rating: Very high
[parent] decimal place (Definition)

A decimal place of a number (a real number) $r$ is the position of a digit in its decimal expansion relative to the decimal point. Let us write $r$ as a decimal number:

$\xymatrix @C=0pt @H=10pt {A_nA_{n-1}\ldots A_1 & \bullet & D_1D_2\ldots D_m \ldots \\ & \save *\txt{the decimal point} \restore \ar[u] & }$
where each of the $A_i$ and $D_j$ is a digit in the decimal system (one of $0,1,2,3,4,5,6,7,8,9$ . In this decimal expansion,
  • the $i$ th decimal place to the left of the decimal point is the position of $A_i$ and
  • the $j$ th decimal place to the right of the decimal place is the position of $D_j$
The digits $A_i$ and $D_j$ are called the decimal place values. $A_i$ is the decimal place value corresponding to the $i$ th decimal place to the left of the decimal point, while $D_j$ is the decimal place value corresponding to the $j$ th decimal place to the right of the decimal point.

For decimal places closer to the decimal point, specific names are used. Below are some of the most commonly used names:

name position from direction from example
  the decimal point the decimal point (position of 7)
ones 1st left $7.2$
tens 2nd left $71(=71.0)$
hundreds 3rd left $735(=735.0)$
thousands 4th left $7126(=7126.0)$
tenths 1st right $0.7$
hundredths 2nd right $12.47$
thousandths 3rd right $9.837$
ten thousandths 4th right $6.0037$

Remark. Instead of saying the $n$ th decimal place to the left or right of the decimal point, we simply say the $n$ th decimal place to mean the $n$ th decimal place to the right of the decimal point, and say $(-n)$ th decimal place to mean the $n$ th decimal place to the left of the decimal point.

For example, in $1632.9758$ the digit $5$ is located on the third decimal place, while $6$ is located on the negative third decimal place.




"decimal place" is owned by CWoo. [ full author list (3) ]
(view preamble | get metadata)

View style:

See Also: metric system

Also defines:  decimal place value, hundreds, thousands, tenths, hundredths, thousandths, ten thousandths

This object's parent.
Log in to rate this entry.
(view current ratings)

Cross-references: negative, decimal number, decimal point, decimal expansion, digit, real number, number
There are 85 references to this entry.

This is version 9 of decimal place, born on 2007-08-08, modified 2008-10-16.
Object id is 9839, canonical name is DecimalPlace.
Accessed 17275 times total.

Classification:
AMS MSC00A05 (General :: General and miscellaneous specific topics :: General mathematics)

Pending Errata and Addenda
None.
Discussion
Style: Expand: Order:
forum policy
autolinker issue by Wkbj79 on 2007-08-09 01:07:19
Because of the appearance of "ones", "tens", etc. in the defines list for this entry, the autolinker is linking the corresponding singulars to this entry as well. I tried to edit the linking policy to prevent this, but whenever I manage to prevent the singulars from linking, the plurals no longer link either. Can anything be done about this?
[ reply | up ]

Interact
post | correct | update request | add derivation | add example | add (any)