That's how mathematics work. You've got whole numbers and you've got decimal numbers... Some happen to be periodical.
Let's say there is a formula (a-b)/9 where a are your kills and b your deaths. The outcome of the formula would be the gold received. Now, say you killed 13 people and died 3 times, a plugin uses the formula with those numbers and gets a fraction 10/9 which it transforms to a decimal number. 10/9 = 1.1111...
You can set how many decimal places the plugin should show as the result. In your case it's set at 13 places, which I guess was the default. Changing this number to something more reasonable shouldn't be a problem in which case I am a +1 on this suggestion.
