# [Tutor] / vs //

**Christopher Smith
**
csmith@blakeschool.org

*Wed, 20 Feb 2002 12:47:13 -0600*

The two operations below yield different results...does / know something
that // doesn't know?
>>>* 3.9//1.3
*2.0
>>>* 3.9/1.3
*3.0
It seems like // is being technically corrrect since 3.9 is a little
smaller than 3.9 but that / is being a little smarter and trying to give
you a closer approximation.
>>>* 3.9
*3.8999999999999999
>>>* 1.3
*1.3
PEP 238 says that a//b should act like floor(a/b) but you can see in this
example that it doesn't since that result is 3.0 not 2.0
>>>* math.floor(3.9/1.3)
*3.0
/c