I am an intermediate student of Russian, and in one of my courses I came across the following example:
Тут два белых стула. — Two white chairs are here.
My understanding is that the genitive is generally used with numbers, and here the adjective белый is declined to the genitive plural белых, so I would expect the noun to also be declined to the genitive plural стульев. However, the example uses the genitive singular стула for "chairs".
Why is this the case, and is there a "rule" that addresses this type of sentence?
For clarity and contrast, here is another example in the genitive that declines the way I was expecting:
У меня нет двух белых стульев. — I do not have two white chairs.