CONVERSION OF UNITS OF LENGTH

Convert the following lengths.

Example 1 :

480 cm to m

Solution :

1 cm = 1/100 m

480 cm = (480)/100 m

= 4.8 m

Example 2 :

54 mm to cm

Solution :

1 mm = 1/10 cm

54 mm = (54)/10 cm

= 5.4 cm

Example 3 :

5280 m to km

Solution :

1 m = 1/1000 km

5280 m = (5280)/1000 km

= 5.28 km

Example 4 :

2000 mm to m

Solution :

1 mm = 1/1000 m

2000 mm = (2000)/1000 m

= 2 m

Example 5 :

580000 cm to km

Solution :

1 cm = 1/100000 km

580000 cm = (580000)/100000 km

= 5.8 km

Example 6 :

7000000 mm to km

Solution :

1 mm = 1/1000000 km

7000000 mm = (7000000)/1000000 km

= 7 km

Example 7 :

Mike ran 8.5 km while mal walked 3200 m. How much farther did Mike run than Mal walk ?

Solution :

Mike runs = 8.5 km

Mal walks = 3200 m

We need to know mike runs (in meters).

8.5 km to m

1 km = 1000 m

8.5 km = (8.5 × 1000) m

= 8500 m

Difference between mile run and mal walk = (8500 - 3200)m

= 5300 m

Converting m to km,

1 m = 1/1000 km

5300 m = (5300)/1000 km

= 5.3 km

So, 5.3 km Mike ran than Mal walked.

Example 8 :

I have 45 coils of fencing wire and each coil is 275 m long. How many kilometres of wire do I have ? 

Solution :

Total length of coil wire = Number of coil wire × Each length of wire

= 45 × 275

= 12375 m

Converting m to km,

1 m = 1/1000 km

12375 m = (12375)/1000 km

= 12.375 km

I have 12.375 km of wire.

Example 9 :

Liesel swims eighty 25 m laps in 1 hour. If she continues to swim at that speed, how many kilometres will she swims in 3 hours ?

Solution :

Liesel swims in 1 hour = 80(25) m

= 2000 m

she swims in 3 hours  =  2000 × 3

= 6000 m

Converting m to km,

1 m = 1/1000 km

6000 m = (6000)/1000 km

= 6 km

she will swim 6 km in 3 hours.

Example 10 :

John has 3.85 km of copper wire and needs to cut it into 1.5 cm lengths to be used in electric toasters. How many lengths can he make ?

Solution :

John has 3.85 km of copper wire.

Converting km to m,

1 km = 100000 cm

3.85 km = (3.85 × 100000) cm

= 385000 cm

He needs to cut it into 1.5 cm lengths.

Required lengths = (385000)/1.5

= 256666

He can make 256666 lengths.