To change "puer" (nominative singular) to accusative plural, you need to first change it to the nominative plural form which is "pueri." Then, to get the accusative plural form, change "pueri" to "pueros."

The accusative word for Pictor in latin is Picturam.

You must mean the word mater (there is no matr). The accusative singular of this is matrem; the accusative plural matres.

The accusative of the word "cubiculum" in Latin is "cubiculum." This is because "cubiculum" is a neuter noun in the second declension, which means that the accusative form is the same as the nominative form.

Accusative.