Simple Yet Devilish Math Problem

I've been trying to decipher the answer to this math question for over a month. It's based on a question that arose from a spell I was trying to make via GUI.

Spell: Attack Dogs
Levels: 5
Dogs Spawn Per Lvl: 1 for lvls 1-2 2 for lvls 3-4 and 3 for lvl 5.

Were there 6 lvls, and of each 2, 2 dogs were spawned this would be simple.. But having an uneven factor makes it extremely complex. Anyone who may be better at math than me, come forward and answer this legendary inquire.

The final equation can be a decimal, but can not be a fraction of a number, or else it will register as 0. As far as I know if you have an integer and you use a real to set it the real being 0.60 for instance, it will register as 0, because integers only accept whole numbers..

.. what exactly do you want to know?

How to produce the number of dogs that the levels have been designated using math.

Usually you would just go, for each 5 levels, multiply once by the level of the ability. But that would create 5 dogs, I want three dogs using 5 levels, which I haven't figured out how to do mathematically.

There are easier ways to do it rather than an equation, but I want to know the answer to this divine question.

Maybe it could be something like this.

1x1=1
2x.5=1
3x.7=2.1
4x.5=2
5x.6=3

The devilish 3 doesn't want to be whole .

When an integer is converted to a Real it is always rounded down.
So 0.6 becomes 0 and 1.6 becomes 1.

The formula:

( level / 2) + 0.5

Lvl 1: ( 1 / 2 ) + 0.5 = 0.5 + 0.5 = 1
Lvl 5: ( 5 / 2 ) + 0.5 = 2.5 + 0.5 = 3

Excellent Math, mine for that matter sucks.