Answer: 4
Step-by-step explanation: "Per box" means in 1 box so we can rewrite the given statement using fractions like I have done in the image below.
To find out what goes in the blank, notice that we
have a 1 in the denominator of our second fraction.
So we want to find a fraction that is equivalent
to 12/3 that has a 1 in the denominator.
If we divide the numerator and denominator of 12/3 by 3,
we get the equivalent fraction 4/1 or 4 cupcakes over 1 box.
So now we have 4 cupcakes over 1 box = __ cupcakes over 1 box.
So a 4 must go in the blank.
So 4 cupcakes per box.
