Even young kids know about measuring as they stand to be measured for height at the doctor's office every year. Some may even have experience using a ruler or measuring tape at home! Still, learning more about units of measurement, time, mass, and more is a necessary part of the elementary math curriculum--why not make it more fun with a cute blue Monster named Mo? Readers learn these basic concepts alongside Mo, practice each concept, and build their knowledge one inch at a time!.