Any Class Help Intelligence And Mana Costs

I have a pretty simple question, but I haven't been able to find any information on it. As can easily be observed, mana costs are visually always rounded up. with, meteor for example, even if you have 74% intelligence, the cost will still say 3, not 2. My question is, does the visual mana cost represent the true mana cost, or is there an underlying fractional system. If the rounding is truly changing the cost, there is no point of having intelligence values in between those that drop the cost of a given spell by one point. With a mage, for example, the cost of their spells are 6, 4, 8, and 4 (All at max level) So, you would want to have your intelligence at certain milestone percentage values. For mage, these would be 12.5%, 16.7%, 25%, 33.4%, 37.5%, 50%, 62.5%, 66.7%, and 75% (14, 19, 29, 41, 47, 68, 94, 105, and 129 skill points.) Notice that the last value is 75%. If mana costs were rounded, there would be no point in having an intelligence stat above 75% (Other than the 5% water damage boost which is extremely minimal.) The difference between 75% and 80% correlates to a cost of 21 skill points. If these 21 skill points did nothing they would make a substantial difference elsewhere.

 

Wynncraft: Values round up almost every single time
Visual cost = true cost