This is a real-world, problem solving activity of math. In the occupation of forestry land management, decisions that are not based on accurate resource measurements may lead to serious errors, misjudgments or financial losses to the parties involved. This unit shows students how to measure the diameter, height, and volume of a tree in order to predict the merchantability of the tree. Though the focus is math, correlation of science standards dealing with ecology can provide excellent, hands-on, real world activities for high school or middle school students in the life sciences. Please note that only the measurements of length, height, volume, and diameter are taught and assessed in this unit.