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Example 8: Convert 366 days into weeks and days. Example 1: Add the following: Note
52
Solution: Since 7 days = 1 week 7 366 (a) 32 minutes 48 seconds + 16 minutes 56 seconds We use ‘h’ for ‘hours’,
366 days = (366 ÷ 7) weeks 35 (b) 6 hours 34 minutes + 8 hours 47 minutes ‘min’ for ‘minutes’, ‘s’ for
seconds for writing units
16 Solution:
Quotient = 52 weeks, Remainder = 2 days 14 of time in short.

Thus, 366 days = 52 weeks 2 days 2 (a) Step 1: Add seconds:
48 seconds + 56 seconds = 104 seconds
min s
= 60 seconds + 44 seconds = 1 minute 44 seconds 1
Knowledge Desk Step 2: Add minutes: 32 48

A leap year has 366 days. Julius Caesar introduced the first calendar leap year in 46 B.C. The 1 minute + 32 minutes + 16 minutes = 49 minutes + 16 56
Earth takes exactly 365 days, 5 hours, 48 minutes and 45 seconds to move around the Sun. 49 44
Thus, 32 minutes 48 seconds + 16 minutes 56 seconds
Practice Time 10A = 49 minutes 44 seconds

(b) Step 1: Add minutes:
1. Convert the following. 34 minutes + 47 minutes = 81 minutes h min

(a) 9 minutes into seconds (b) 12 minutes 54 seconds into seconds 81 minutes = 60 minutes + 21 minutes 1

(c) 3 hours 25 minutes 16 seconds into seconds = 1 hour 21 minutes ( 1 hour = 60 minutes) + 6 34
8
47
Step 2: Add hours:
(d) 14 hours into minutes (e) 9 hours 54 minutes into minutes 15 21
1 hour + 6 hours + 8 hours = 15 hours
(f) 7 days into hours (g) 8 days 19 hours into hours 6 hours 34 minutes + 8 hours 47 minutes = 15 hours 21 minutes

(h) 7 weeks 3 days into days (i) 3 years into days Example 2: Subtract the following:

(j) 10 years into months (k) 5 years 10 months into months (a) 48 minutes 34 seconds from 54 minutes 20 seconds

2. Convert the following into minutes and seconds. (b) 7 hours 54 minutes from 13 hours 22 minutes
(a) 1318 seconds (b) 3165 seconds Solution:

3. Convert the following into hours and minutes. (a) Step 1: Subtract seconds. There are not enough seconds.
s
(a) 238 minutes (b) 498 minutes (c) 1032 minutes (d) 3024 minutes So, regroup minutes and seconds. min 80
53
4. Convert the following into days and hours. 54 minutes 20 seconds = 53 minutes 80 seconds 54 20

(a) 57 hours (b) 537 hours (c) 953 hours (d) 1810 hours Now, 80 seconds – 34 seconds = 46 seconds – 48 34
5
46
5. Convert the following into weeks and days. Step 2: Subtract minutes:
53 minutes – 48 minutes = 5 minutes
(a) 330 days (b) 438 days
54 minutes 20 seconds – 48 minutes 34 seconds = 5 minutes 46 seconds

OPERATIONS ON TIME UNITS (b) Step 1: Subtract minutes. There are not enough minutes. h min

Addition and Subtraction of Measures of Time So, regroup hours and minutes 12 82
13 hours 22 minutes = 12 hours 82 minutes 13 22
We can perform operations on time units as we did for length, weight and for capacity. – 7 54
Now, 82 minutes – 54 minutes = 28 minutes
To perform addition or subtraction of time, we arrange the same units of time in same Step 2: Subtract hours: 12 hours – 7 hours = 5 hours 5 28
columns and then add or subtract. 13 hours 22 minutes – 7 hours 54 minutes = 5 hours 28 minutes

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