Write and present your own ingredients list. Use word reference online dictionary to see if the word is masculine or feminine before deciding if it's going to be un, una, unos, unas. You could make an ingredients list for:
a happy life
a great school
a good meal
a disgusting soup
You could also use the words mucho/mucha/muchos/muchas to mean 'a lot of' - look how this also agrees.
In this video you will learn how to say 'a' and 'some' after revising the four ways of saying 'the'.
You need to change the options to 'see term first' for this activity: