Introduction to Elapsed Time

Elapsed time connects clock-reading to subtraction and builds the planning skills children need for managing their own time.

• Framework: Montessori
• Unit: Mathematics
• Learning area: Measurement
• Level: Ages 5-6

Objectives

• Calculate time that has passed
• Use clock to count hours
• Solve elapsed time problems

Materials

• Demonstration clock
• Individual clocks
• Elapsed time problem cards
• Number line for hours
• Recording sheet

Instructions

1. Set clock to 9:00. 'We started at 9 o'clock.' 2. Set to 11:00. 'Now it's 11 o'clock.' 3. 'How long have we been working?' Count hours: 2 hours. 4. Try: 'Started at 1:00, finished at 4:00.' (3 hours) 5. Introduce half hours: '2:00 to 3:30 is 1 and a half hours.' 6. Connect to daily schedule.

Educator tip

Start with whole hours before introducing half hours. A number line marked in hours helps visualize the counting.

Assessment

Child calculates elapsed time in hours and half hours.

More from Mathematics

• Subtraction as Finding the Difference
• Cube Chains and Square Numbers
• Introduction to Simple Equations
• Mathematical Journal Writing
• Montessori Math Fair Projects
• Number Rods
• Sandpaper Numerals
• Spindle Boxes