Hi Leslie,

Go to the Quandaries and Queries page on Math Central and use the Quick Search to search for the term fact family. You will see a number of responses we have given to questions concerning fact families. In particular read Judi's response to the question What is a Fact Family? Judi's response is for situations where the arithmetic operations are addition and subtraction. Since you have 4, 4 and 16 in your fact family and $4 \times 4= 16$ I think your fact family is formed from multiplication and division. In this case I suggest you look at my response concerning fact families formed using multiplication and division. Since 4 divided by 4 is 1 I think your family should have four members, 1, 4, 4, and 16.

I hope this helps,
Penny