Perhaps ten families is too many, and you would prefer to do only a few - or perhaps your students are just becoming competent at the activity when they finish the ten families, and you will make up more of your own.

If you decide to give ten CALCULATIONS sheets to each student, you might feel that that's too much paper (even double-sided). If so, you could put the CALCULATIONS form on an overhead transparency (either on an overhead projector or not), and have students use erasable markers.

You might create a computer spreadsheet that would do the calculations, requiring the students only to type in each family's children and their ages.

Anything goes!