Telling Time with Analog and Digital Clocks
Grade 4 introduces the full skill of clock reading: analog (12-hour), digital (both 12-hour and 24-hour), and the fractional language of half past and quarter to. The fractional connection is mathematically powerful: the clock face is a circle divided into 60 equal minutes, and 15 minutes is one quarter of 60, so quarter past and quarter to are fractions of the hour. Traditional First Peoples time-keeping using celestial and environmental cues connects time to ecological knowledge.
Analog clock reading
The short hand shows hours; the long hand shows minutes. The minute hand travels the full circle in 60 minutes: at 12 it is 0 minutes; at 3 it is 15 minutes (quarter past); at 6 it is 30 minutes (half past); at 9 it is 45 minutes (quarter to the next hour). Reading to the nearest minute requires counting the minute marks individually.
12-hour and 24-hour formats
12:00 noon and 12:00 midnight are often confused. The 24-hour clock eliminates ambiguity: 00:00 is midnight, 12:00 is noon, 13:00 is 1 p.m., 23:59 is one minute before midnight. Converting: hours from 13 to 23 in 24-hour format equal hours minus 12 in 12-hour format. The 24-hour clock is used by the military, airlines, hospitals, and railways.
Traditional time-keeping
The BC curriculum highlights First Peoples use of celestial bodies and natural cycles for time determination: the position of the sun indicates time of day; moon phases indicate time within a month; stars indicate seasons and time of year. Navigation by stars (Polaris for North, other constellations for seasons) required sophisticated astronomical knowledge. These systems demonstrate that time measurement is not dependent on clocks.