Chem Tutor
Chem Tutor: Conversions Using Dimensional Analysis
Practice problems with answers for converting units with dimensional analysis.
Other
Brown Math: How to Convert Units of Measurement
This site has a detailed step-by-step instruction of how to convert units of measurement. Multiplying by 1 is explained as are compound units, and finding conversion factors. The discussion is slowed down for students who may have missed...
Khan Academy
Khan Academy: Convert Units (Metrics)
Convert between metric measures of distance, volume, and mass. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
National Council of Teachers of Mathematics
The Math Forum: Measurement: Metric Conversions
This lesson plan has a game to help students convert to various linear metric units and learn their abbreviations.