# Measuring Time.

## Presentation on theme: "Measuring Time."— Presentation transcript:

Measuring Time

Time is measured in; Y_________ M_________ W_________ D_________
H_________ S_________

A year has _____ months. A year has _____ weeks. A year has _____ days. A month has between ___ and ___ days. A week has _____ days. A day has _____ hours. A hour has _____ minutes. A minute has _____ seconds. 12 52 365 28 31 7 24 60 60

How many seconds in 5 minutes?
60 x 5 = 300 How many minutes in 10 hours? 60 x 10 = 600 How many months in 200 years? 12 x 200 = 2400 How many weeks in 2 years? 52 x 2 = 104 How many days in 9 weeks? . 7 x 9 = 63

How many seconds in an hour?
60 x 60 = 3600 How many hours in a week? 24 x 7 = 168 How many seconds in a year? 60 x 60 x 24 x 365 =

Clocks We usually use clocks and watches to measure time.
Clocks usually just display hours and minutes. Hours : Minutes 3 : 15 But sometimes also display seconds Hours : Minutes : Seconds 3 : 15 : 23 Sometimes clocks do not have the : separating the numbers.

There are two main types of clocks;
12 hour clocks. 24 hour clocks. A 12 hour clock counts from 1 to 12 in the morning then starts again in the afternoon. Morning is labelled ____. Afternoon is labelled ____. A 24 hour clock simply counts from 0 to 23.

Changing Times: 12  24 When you want to change from a 12 hour time to a 24 hour time you sometimes add 12. If the time is after 1 pm ADD 12. If it is a morning (__M) time do NOT ADD 12. If it is a morning time that starts with 12 (right after midnight) then the 24 hour time starts with 0.

Changing Times: 24  12 When you want to change from a 24 hour time to a 12 hour time you sometimes take away 12. If the 24 hour time is more than 12, take away 12. If the 24 hour time is less than 12, DO NOT take away 12. If the 24 hour time starts with a 0, the 12 hour time starts with a 12.

Change these 12 hour times into 24 hour times.
12 Hour Time 24 Hour Time 7:43 am _________ 7:43 pm _________ 2:28 pm _________ 1:00 am _________ 11:59 am _________ 12:04 pm _________ 3:40 pm _________ 6:00 pm _________ 9:14 am _________ 12:34 am _________ 0743 1943 1428 0100 1159 1204 1540 1800 0914 0034

Change these 24 hour times into 12 hour times.
24 Hour Time 12 Hour Time ____:_____ __ __ ____:_____ __ __ ____:_____ __ __ ____:_____ __ __ ____:_____ __ __ ____:_____ __ __ ____:_____ __ __ ____:_____ __ __ ____:_____ __ __ 2400 or ____:_____ __ __ am am pm pm pm am am pm am am

How many hours and minutes between….
9.15am and 11.32am? 4:12 am and 1634? 11.00am Friday and 2.30pm Sunday? 2 hours and 17 minutes 12 hours and 22 minutes 51 hours and 30 minutes