I am familiar with the words in Irish for numbers. I think that there are different words for counting objects.

For example, could you translate for me:
"How many books are there?"
"There is one book. There are two books. There are three books." (up to ten)

Would you use the same number words if you were talking about other objects, like pencils for instance? Does the noun change spelling when counting objects?

How about for adding numbers? What number words do you use in this case?

For example, could you translate for me:
"How much is two and two? Two and two is four"

Cá mhéad a dheineann a dó agus a dó? A dó agus a dó, sin a ceathair.
An mó a dheineann a dó agus a dó?

An mó leabhar atá ann? Tá leabhar amháin ann, tá dhá leabhar ann (tá cúpla leabhar ann), tá trí leabhair ann.
Cá mhéad leabhar atá ann?

Mhéad: pronounced vi-ad.

Thank you so much!