# Ruby arithmetic operations =S **URL:** \ **Category:** Ruby\ **Created:** [November 16, 2006, 11:46pm UTC](https://www.ruby-forum.com/t/ruby-arithmetic-operations-s/76253 "2006-11-16T23:46:09Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![flaab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@flaab](https://www.ruby-forum.com/u/flaab)\ **Post date:** [November 16, 2006, 11:46pm UTC](https://www.ruby-forum.com/t/ruby-arithmetic-operations-s/76253/1 "2006-11-16T23:46:09Z")
Hi there I have to do a program for the first time that needs some math…and which is my surprise that num mod num to get the modulus of a division does not work! neither num div num to the the integer result of it. All the rest of math operands work fine xDDD But how do i do: a) A float division ( 5 / 2 = 2.5) b) A mod division ( 5 mod 2 = 1) c) An integer division =S (5 div 2 = 2) Thx! xD ---
**Author:** ![flaab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@flaab](https://www.ruby-forum.com/u/flaab)\ **Post date:** [November 16, 2006, 11:54pm UTC](https://www.ruby-forum.com/t/ruby-arithmetic-operations-s/76253/2 "2006-11-16T23:54:18Z")
> All the rest of math operands work fine xDDD But how do i do: > > a) A float division ( 5 / 2 = 2.5) > b) A mod division ( 5 mod 2 = 1) > c) An integer division =S (5 div 2 = 2) > > 5 / 2.0 > > =\> 2.5 > > > 5 % 2 > > =\> 1 > > > 5 / 2 > > =\> 2 > > > In ruby when you divide integers, you get integer division. If you want float, use floats (just add point zero). Regards, Rimantas ---
**Author:** ![flaab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@flaab](https://www.ruby-forum.com/u/flaab)\ **Post date:** [November 17, 2006, 12:26am UTC](https://www.ruby-forum.com/t/ruby-arithmetic-operations-s/76253/3 "2006-11-17T00:26:28Z")
Flaab M. wrote: > Hi there > > I have to do a program for the first time that needs some math…and > which is my surprise that num mod num to get the modulus of a division > does not work! neither num div num to the the integer result of it. > > All the rest of math operands work fine xDDD But how do i do: > > a) A float division ( 5 / 2 = 2.5) 5.0 / 2.0 = 2.5 > b) A mod division ( 5 mod 2 = 1) 5 % 2 = 1 > c) An integer division =S (5 div 2 = 2) 5 / 2 = 2 The point is, you tell the language what you want by specifying the numeric type. Floats have a decimal point and one or more digits to the right, even if only a zero. Integers don’t. ---
**Author:** ![flaab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@flaab](https://www.ruby-forum.com/u/flaab)\ **Post date:** [November 17, 2006, 12:32am UTC](https://www.ruby-forum.com/t/ruby-arithmetic-operations-s/76253/4 "2006-11-17T00:32:30Z")
> > > 5 / 2.0 > > > =\> 2.5 > > > > > 5 % 2 > > > =\> 1 > > > > > 5 / 2 > > > =\> 2 > > > > > > In ruby when you divide integers, you get integer division. If you > want float, use floats (just add > point zero). It’s not quite so simple. > > 5/2 > > =\> 2 > > > require ‘mathn’ > > =\> true > > > 5/2 > > =\> 5/2 > > …where the last “5/2” is a rational number. If you want to do > > integer division “portably” (i.e., in a way that is compatible with the > > mathn standard library having been required earlier in the program), > > you should use “div” > > > 5.div(2) > > =\> 2 > > > 5.modulo(2) > > =\> 1 > > > 5.divmod(2) > > =\> [2,1] > > If you wish to use the Rational, Complex, or Matrix classes in the > > standard library, you will need to require mathn to avoid strange and > > even downright buggy behavior. But this redefines the meaning of > > expressions like 5/2. ---
**Author:** ![flaab](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/f/dbc845/32.png) [@flaab](https://www.ruby-forum.com/u/flaab)\ **Post date:** [November 17, 2006, 10:15pm UTC](https://www.ruby-forum.com/t/ruby-arithmetic-operations-s/76253/5 "2006-11-17T22:15:30Z")
----- Original Message ----- From: “Flaab M.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Newsgroups: comp.lang.ruby To: “ruby-talk ML” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Sent: Thursday, November 16, 2006 5:46 PM Subject: Ruby arithmetic operations =S > c) An integer division =S (5 div 2 = 2) > > Thx! xD > > – > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). float division x = 5.0 / 2 or x = 5 /2.0 or x 5.0/2.0 mod division x = 5 % 2 integer division x = 5 / 2