Lesson 3: The Clock-In: Calculating Elapsed Time
Duration of Days: 7
Lesson Objective
Students will calculate total hours worked from a "Time In/Time Out" log, including subtracting unpaid lunch breaks.
If I start at 8:15 AM and leave at 4:45 PM, how many hours was I there? Why does my boss take 30 minutes off my total?
AM/PM
Military Time
Elapsed Time
Rounding (to the nearest quarter hour)
Lunch Deduction.
CCSS.MATH.CONTENT.3.MD.A.1
Description: Students practice converting "Time Clock" stamps into decimal hours (ex. 30 mins = 0.5 hours).
Purpose: To ensure students can verify their own hours on a paycheck.
DOK Level: 2
Provide a "Decimal Conversion Chart" (15 min = .25, 30 min = .50); use analog clock manipulatives for visual learners.
Correctly calculating a weekly total from a 5-day mock timecard with varying start/end times.
Mock timecards
"Time-to-Decimal" cheat sheets.