There are $144$ items in a gross. There are $12$ items in a dozen. How many dozens are there in a gross?

Hint: We will formulate an equation between the given units of quantities i.e., between a gross and dozens. Since there are $144$ things in a gross and $12$ in a dozen, we can say that if y dozen are there in a gross, then we can write: $12y = 144$. Solving this equation, we can get the value of the number of dozens in a gross.

Complete step-by-step answer:
We are given that a gross has $144$ items and $12$ items are there in a dozen.
We are required to calculate how many dozens are there in a gross.
Now, we can say that if there are $'y'$ dozens in a gross then formulating an equation, we can write that: $y$ dozen = $1$ gross.
 If there are $12$ items in a dozen and $144$ items are in a gross, then the equation can be written as:
$ \Rightarrow y \times 12 = 1 \times 144$
Solving this equation for the value of y, we get
$ \Rightarrow y = \dfrac{{144}}{{12}}$
$ \Rightarrow y = 12$
Therefore, there are $12$ dozen in gross.

Note: In mathematics, a gross is a unit of capacity and it basically refers to a group of any $144$ items or things. It is also referred to as a dozen – dozen or a square dozen i.e., ${\left( {12} \right)^2} = 144$ but a small gross refers to a group of $120$ items. And a dozen is referred to a group of $12$ items or things. It is one of the earliest units of groupings.