Hi Jon, in Chinese we call that liàng cí or ‘Measure Word’. English speakers should be familiar with ’Measure Word ’ as the type of object being discussed, as in a “loaf” of bread, or a “stick” of gum, a “bouquet” of flower and so on

The main difference between English and Mandarin is that Mandarin requires a measure word for every noun. For example, In English we say, “three cars,” but in Mandarin , we need to say “three (measure word) cars.”

There are more than a hundred Mandarin measure words, and the only way to learn them is by memorizing them. So, whenever you learn a new noun, you should also learn its measure word.

Visit this link below to get some examples of measure words
http://www.languagerealm.com/chinese/measure_words_ch.php

cheers