Students estimate and then measure some simple lengths, first with candy bars of varying lengths and then with toothpicks of uniform length. They gain an appreciation of the importance of measuring with units of standard, though unconventional, length. The lesson stops short of having students notice that units of different length produce different measurements, but teachers could easily make this point based on the activities. Teachers may also want to clarify the difference between an estimate and a guess, as the lesson plan uses the terms interchangeably. An activity sheet, ideas for extensions and assessment, and Internet links are included. (sw)