Can someone help me set this problem up to solve it?

Question

My son is in 4th grade and needs help with knowing how to set this problem up to solve it.  They have not learned division yet and of course have been taught the common core method of drawing boxes and whatnot, which makes no sense to me.  They are learning to solve for "n", but can't do division to solve it.  It's frustrating.  Help please!  Thank you!

 

Ethan served 24 familes at his job on Monday and Tuesday.  He served twice as many families on Tuesday than Monday.  How many families did he serve on Monday?

Answer 1

Although he hasn’t done division, he will have done his times tables.

So, on Monday, he served a group of families of a certain size (the size of the group not the size of the families!). On Tuesday, he served two more groups of people, so in all he served three groups of families.

What is the size of the group? How many families in the group? In other words, three times what equals 24?

We get to three times eight. Bingo! So the group size is 8 families. 8 on Monday, two times eight on Tuesday is sixteen. 16 families on Tuesday.