Plural ending with the numbers?

One tricky thing about Turkish is that "we don't make the nouns plural with the numbers". 

What does it mean? 

If you say "iki adam"/two men, it is enough, we do not add ler/lar to "adam"-which is a noun. 

So,

iki uzun adam - two long men

üç çirkin kız - three ugly girls

dört şişman kedi - four fat cats

beş büyük, şişman ve tembel köpek - five big, fat and lazy dogs 

But,

uzun adamlar - long men , there is no number describing the noun, so we add the plural suffix.

I hope that you know the rule even better now !