Found this cute activity over at http://stepintosecondgrade.blogspot.com/search/label/measurement
The students have already been learning about measurement (inches, feet, yards) and our next chapter is about metric units (centimeters, meters).
I read the story "Inch by Inch" by Leo Lionni to the students and showed them that the ruler is a measuring tool for both inches and centimeters.
Each student drew a picture of an animal onto their white paper. They colored, cut out, and measured the height and width of their animal in centimeters. Next year, I will have them measure in inches and centimeters to compare the different units.