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mULTiPLiCATiOn AnD DivisiOn Of UniTs Of TimE

Example 1: Multiply 4 hours 15 minutes 30 seconds by 4.

Solution: Step 1: Multiply 30 seconds by 4. h min s

30 seconds × 4 = 120 seconds 2
4 15 30
Convert 120 seconds into minutes and seconds. × 4
00
120 seconds = 2 × 60 seconds = 2 minutes

Carry 2 minutes to the minutes column and write 00 seconds in the
seconds column.

Step 2: Multiply 15 minutes by 4 and add the carry over (2 minutes) to the

product. h min s
15 minutes × 4 + 2 minutes = 62 minutes 1 2

Convert 62 minutes into hours and minutes. × 4 15 30
4
62 minutes = 1 hour and 2 minutes 02 00
Carry 1 hour to the hours column and write 2 minutes in the minutes

column as a 2-digit number.
Step 3: Multiply 4 hours by 4 and add the carry over (1 hour) to the product.

4 hours × 4 + 1 hour = 17 hours
h min s
Write 17 hours in the hours column. 1 2

Thus, the required product is 17 h 02 min 00s. 4 15 30
× 4
Example 2: Divide 16 hours 32 minutes 40 seconds by 5. 17 02 00

Solution: Step 1: Divide 16 hours by 5. 3 hours
Write 3 hours as the quotient and 1 hour as 5 16 hours

the remainder. 15
1 hour
Step 2: Convert the remainder 1 hour into minutes and
add 32 minutes to it.

60 minutes + 32 minutes = 92 minutes
Step 3: Divide 92 minutes by 5. 18 minutes

Write 18 minutes as the quotient and 5 92 minutes
5
2 minutes as the remainder. 42
40
2 minutes
Step 4: Convert the remainder 2 minutes into seconds
and add 40 seconds to it.

(2 × 60) seconds + 40 seconds = 160 seconds

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