This activity / assessment has 16 questions where the student fills in the factor tree. It is a great way to start the kids thinking about factoring polynomials. it will also tell you who knows their multiplication tables.
The students who could do these were able to factor more easily and were more likely to be able to apply it to factoring polynomials like
x^2 + 10x +21
I put in an answer key too so you could leave this with a substitute teacher :-)