Learn Italian: Ci sono sessanta studenti qui. - There are sixty students here.

No, cardinal numbers like sessanta (sixty) are invariable. This means their endings never change, regardless of whether the noun they describe is masculine or feminine. It will always be sessanta.

Why do we use ci sono instead of just saying sono?

Ci sono translates to "there are" when talking about existence or presence. If you just used sono ("they are"), the sentence would mean "They are sixty students here." We use ci sono (the plural of c'è, "there is") to state that the students are present in a location.

Why does studenti end in "i" to make it plural?

In Italian, you don't add an "s" to make a word plural like in English. Instead, you change the final vowel. The singular word for student is studente. Nouns that end in "e" in the singular change their ending to an "i" in the plural.

Could the word qui go somewhere else in the sentence?

Yes! You could also say Qui ci sono sessanta studenti. Both are completely correct. Placing qui (here) at the end of the sentence is very natural, while putting it at the beginning adds slightly more emphasis to the location.