"Children are eating some pasta."
Translation:Des enfants mangent des pâtes.
L+ apostrophe introduces a singular noun starting with a vowel or a non aspired H : l'enfant, l'ami, l'homme. Therefore, you have to use the plural form: LES
"pâtes" in French, when it means "pasta" is feminine plural. Therefore, you have to use the DES article, which is the contraction of DE-LES, where "DE" is a partitive preposition (meaning: a certain quantity of).
The closer sentence to your proposal would be "L'enfant mange de la pâte", which means "the child is eating (some) dough".