Time Primary 4 Mathematics

Chapter Learning Outcomes Telling time in seconds Understanding and using the 24-hour clock Solve word problems related to time

Time In Seconds There are three hands on this clock. This is the hour hand. This is the minute hand. This is the second hand.

Time In Seconds I can recall that 1 hour = 60 minutes. Well, 1 minute = 60 seconds! We use s to stand for seconds. Use a stopwatch to see what you can do in 1 second!

Time In Seconds 3.00 p.m. after 30 s 3.01 p.m. after 30 s

What is the time shown on the clock? The 24-hour Clock What is the time shown on the clock? 9.30 a.m. Nine thirty a.m. Using 12-hour clock 09 30 Zero nine thirty hours Using 24-hour clock

What is the time shown on the clock? The 24-hour Clock What is the time shown on the clock? 10.00 p.m. Ten p.m. Using 12-hour clock 22 00 Twenty-two hundred hours Using 24-hour clock

The 24-hour Clock

Example Fill in the blanks. 12-hour clock 24-hour clock 4.30 a.m. 17 20 3.15 p.m. 02 05 Noon 21 55 12.40 p.m. 05 05 04 30 5.20 p.m. 15 15 2.05 a.m. 12 00 9.55 p.m. 12 40 5.05 a.m.

I can solve this using a time line. Word Problems Arianne started reading the newspaper at 18 00. She finished reading at 19 20. How long did she take to read the newspaper? I can solve this using a time line. She took 1 h 20 min.

Count backwards on the time line. Word Problems Justin finished cooking his lunch at 13 45. He took 2 h 10 min to cook. At what time did he start cooking his lunch? Count backwards on the time line. He started cooking at 11 35.

Example Andy took a flight from Melbourne to Singapore which lasted 9 h 30 min. He stopped in transit for 2 h before taking a connecting flight to Penang for 1 h 15 min. If he landed at 08 30 on Tuesday, when did he leave Melbourne? He left Melbourne at 19 45 on Monday.

Example Jermaine started watching a movie marathon at 19 30. He finished watching the movies at 02 45 the following day. How long was the movie marathon? 4 h 30 min + 2 h 45 min = 6 h 75 min = 7 h 15 min The movie marathon lasted 7 h 15 min.

Reference - Textbooks Learning Outcomes Telling time in seconds 4B Pg 81 – 85 4B Pg 64 – 67 Understanding and using the 24-hour clock 4B Pg 86 – 89 4B Pg 68 – 71 Solve word problems related to time 4B Pg 89 – 97 4B Pg 72 – 76