National Council of Teachers of Mathematics
Nctm: Figure This: How Much Time Do Teens Spend on the Job?
Try this math challenge where you investigate the average number of hours teen actually spend working. Apply your problem solving, number sense, and computation skills in this one page activity from the NCTM Math Challenges for Families...
Khan Academy
Khan Academy: Converting Units of Time Review
Resource reviews seconds, minutes, and hours, and how to convert between them then provides practice problems.