# Decimal Operations
**URL:** https://discussions.unity.com/t/decimal-operations/66989
**Category:** Questions & Answers
**Created:** [March 26, 2013, 6:11pm UTC](https://discussions.unity.com/t/decimal-operations/66989 "2013-03-26T18:11:56Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@sgmongo](https://discussions.unity.com/u/sgmongo)
#### Post date: [March 26, 2013, 6:11pm UTC](https://discussions.unity.com/t/decimal-operations/66989/1 "2013-03-26T18:11:56Z")
Alright, I have a question about how unity deals with decimal operations because it seems odd at times.
#pragma strict
var float1 : float = .4;
var float2 : float = .5;
function Start () {
```
Debug.Log( float1 - float2 ); // Yields: -0.099999999
Debug.Log(".4 - .5 = " + ( .4f - .5f )); // Yields: -0.1
Debug.Log(".4 - .5 = " + ( .4 - .5 )); // Yields: -0.1
```
}
The yeild: is what is returned in the console. I’m not understanding the first line giving a -0.09999… as its value. I searched around and only found: [Int Vs float operations](http://answers.unity3d.com/questions/55447/unity-cant-do-simple-maths.html) thread, however since this script specifically declares the numbers as floats I’m a little at a loss. I had heard (over a year ago on a tutorial somewhere) that you should toss a letter, like the “f” used in the second debug to ensure proper mathematical operations. Can anyone explain this to me simply?
---
### Author:  [@whydoidoit](https://discussions.unity.com/u/whydoidoit)
#### Post date: [March 26, 2013, 6:13pm UTC](https://discussions.unity.com/t/decimal-operations/66989/2 "2013-03-26T18:13:51Z")
-0.099999999999 is as close to damnit -0.1 and that’s the problem with floats, they give you results like this all the time. It’s why you should never compare them with ==