Page 163 - ICSE Math 4

6. Convert the following to minutes and seconds.
(a) 848 seconds (b) 560 seconds

(c) 1,009 seconds (d) 600 seconds

7. Convert the following to hours, minutes and seconds.

(a) 3,254 seconds (b) 4,800 seconds (c) 6,666 seconds

(d) 9,321 seconds (e) 4,740 seconds (f) 7,296 seconds
Addition of Time

To add me, we follow the given steps.

• Add the seconds together. If the number of seconds is 60 or more, then

(a) subtract 60 from the number of seconds and increase the number of minutes by 1.
(b) repeat the process if the number of seconds is s ll 60 or more.

(c) write the seconds le in the seconds column.

• Add the minutes together.
• If the number of minutes is 60 or more, then

(a) subtract 60 from the number of minutes and increase the number of hours by 1.

(b) repeat this process if the number of minutes is s ll 60 or more.

(c) write the minutes le in the minutes column.

• Add the hours together.
Example 8: Add 3 hours 15 minutes 30 seconds and 2 hours 35 minutes 35 seconds.

Solu on: Step 1: Add the seconds fi rst. h min s
1
30 s + 35 s = 65 s 3 15 30
65 s = 60 s + 5 s + 2 35 35

= 1 min 5 s 5 51 5

Write 5 under the seconds column and carry over 1 to minutes column.

Step 2: Add the minutes.

1 min (carry over) + 15 min + 35 min = 51 min
Write 51 under the minutes column.

Step 3: Add the hours.

3 h + 2 h = 5 h
Write 5 under the hours column.

So, 3 h 15 min 30 s + 2 h 35 min 35 s = 5 h 51 min 5 s.

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