10% of 69 = 8 ?!?!?

[TwoFaced]

I came across this while playing Civ4. Take a look at the breakdown of gold in the top left corner of the first screen shot. Apparently 10%of 69 is 8.

So according to Civ4 my base commerce of 46 yields me 21 gold. Now take a look at the breakdown of gold in second screen shot. Same city same turn just moved a citizen to a different tile resulting in a base commerce of 47 and yet my gold recieved goes down to 20. Notice this time the calculation is correct...10% of 70 is 7.

For some reason the calculation isn't being made correctly in the first example resulting in more commerce than I should have received. Very odd.

First Example:




Second Example:

 

[karadoc]

I've seen something similar. I had 0% of something = 2. I figured it must be getting the extra coins from some other effect, such as specialist or something like that.

 

[TwoFaced]

I discovered this isn't a bug at all.

What happens is fractional values calculated from science and culture get rounded down. The lost fractions are then added to the gold recieved, essentially compensating you for the science and culture you lose do to rounding.