Students identify what type of fingerprint they have.  We learn that our fingerprints are unique, no one has the same exact print, some identifiers include, a loop, an arch, or a whorl.  The students create their fingerprints using washable marker, and compare their print to other students in the group.  Then we report what each student found out, and add up the different types of fingerprints to see what is the most common, and most students have the loop.