80 likes | 212 Views
Time. By: Rosarman Abd.Wahid 02B2557 B.Ed. Primary Education (Mathematics and Science Education). 1 hour = 60 minutes 1 minute = 60 seconds. Example 1: Express 2 h 45 min in minutes . 2 h 45 min = 2 h + 45 min = (1 h + 1 h) + 45 min
E N D
Time By: Rosarman Abd.Wahid 02B2557 B.Ed. Primary Education (Mathematics and Science Education)
1 hour = 60 minutes1 minute = 60 seconds Example 1: Express 2 h 45 min in minutes. 2 h 45 min = 2 h + 45 min = (1 h + 1 h) + 45 min = 60 min + 60 min + 45 min = 165 min Therefore, 2 h 45 min = 165 min
1 hour = 60 minutes1 minute = 60 seconds Example 2: Express 215 min in hours and minutes. 215 min = 60 min + 60 min + 60 min + 35 min = 1 h + 1 h + 1 h + 35 min = 3 h + 35 min Therefore, 215 min = 3 h 35 min
PROBLEMS ON TIME The school starts at 0745 and ends at 1230. How many hours and minutes do the pupils spend in school?
Since we cannot subtract 45 min from 30 min, we have to take 1 hour from 12 hours. Method 1 • By subtraction Answer: They spend 4 hours and 45 minutes in school.
45 min 1 hour 1 hour 1 hour 1 hour Method 2 • By counting forward From the above, we have: (1 h + 1 h + 1 h + 1 h ) + 45 min = 4 h 45 min. Answer: They spend 5 hours and 15 minutes in school.