I got this idea from my peer teacher, Nina. It's a great way for students to share about themselves. I think it would be perfect for a first day of school activity. I would start by having the students first write the numbers. Later, once we have learned about multiplication and division, I would have them create the equations. Finally, they can put it all together in time for Open House.
It can be easily adapted for the younger grades by using addition and/or subtraction. It can be adapted for older grades with exponents, multi-step problems, and including fractions or decimals. Thanks to my friend Nannette for inspiring me with her sample.