One of the most challenging activities in the middle school science lab is taking measurements. A simple ruler can send students into a questioning mob around a teacher, not unlike a shark-feeding frenzy. Student activities that require using and reading a thermometer can cause teachers to lose their hair from the strain of pulling on it with frustration. Then there is the dread of teaching metrics, or the SI system (International System of Units) as it is now termed in most science texts. However, these training exercises can have the opposite effect when designed for practice and application.