Page 171 - ICSE Math 5

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12 Time and Moneyime and Money

Learning Outcomes

Students will be able to learn:
 about larger and smaller units of time and money.
 the conversion of time and money from larger to smaller units and vice versa.
 to solve daily life problems involving time and money.

Time

We know that there are two types of clocks: a 12-hour clock and a 24-hour clock. The time from
12 midnight to 12 noon is expressed as a.m. while the time from 12 noon to 12 midnight is
expressed as p.m.

The format of a 24-hour clock is hours : minutes or hours : minutes : seconds.

We have already learnt the following conversion of days, hours and minutes.
1 day = 24 hours 1 hour = 60 minutes

1 minute = 60 seconds 7 days = 1 week

1 year = 365 or 366 days (in case of a leap year)

Conversion of Days to Hours and Vice Versa

We can convert days to hours and hours to days as follows:

1 day = 24 hours (h) and 1 hour (h) = 1 day
24

• To convert days and hours to hours, multiply the given days by 24 and add the given hours
to it.

• To convert hours to days and hours, divide the given hours by 24. Write the quotient
obtained as number of days and remainder as number of hours.
Example 1: Convert (a) 5 days and (b) 7 days 14 hours to hours.

Solution: (a) 5 days = 5 × 24 hours = 120 hours

(b) 7 days 14 hours = (7 × 24) hours + 14 hours
= 168 hours + 14 hours = 182 hours

Example 2: Convert 640 hours to days and hours.

Solution: 640 hours = 640 (since 1 hour = 1 day)
24 24
= 26 days 16 hours

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