This math topic focuses on calculating negative elapsed time concerning hours and half hours. Specifically, students practice subtracting half an hour from a given time and determining the new time. The problems involve basic time subtraction skills and understanding how clock times adjust backward by 30-minute intervals. Each question provides a start time (e.g., 9:30, 6:30), instructs to subtract 30 minutes, and asks for the time result after the subtraction. There are multiple-choice answers presented for each problem.

Work on practice problems directly here, or download the printable pdf worksheet to practice offline.