OPERATIONS WITH METRIC UNITS WORD PROBLEMS

Problem 1 :

John rode 2 kilometers on his bike. His sister Sally rode 3000 meters on her bike. Who rode the farthest and how much farther did they ride (answer in km)?

Solution :

Distance covered by John on his bike = 2 km

His sister has covered the distance of 3000 m

1 km = 1000 m

Converting m to km, we are converting the smaller unit to the larger unit. So, we have to divide by 1000.

3000 m =- 3000/1000

= 3 km

His sister has covered the long distance and 1 km.

Problem 2 :

Jessica is measuring two line segments. The first line segment is 30 cm long. The second line segment is 500 mm long. How long are the two line segments together? (answer in cm)

Solution :

Length of the first line = 30 cm

Length of the second line = 500 mm

1 cm = 10 mm

Converting mm to cm, we have to divide by 10

500 mm = 500/10 ==> 50 cm

Problem 3 :

Lois wants to send a box of oranges to a friend by mail. The box of oranges cannot exceed a mass of 10 kg. If each orange has a mass of 200g, what is the maximum number she can send?

Solution :

The capacity of the box = 10 kg

Weight of each oranges = 200 g

1 kg = 1000 gram

Converting grams to kg, we have to divide by 1000

= 200 / 1000

= (2/10) kg

Number of oranges she can pack in the box = 10 / (2/10)

= 50 oranges

Problem 4 :

Walt grew 10 centimeters in 1 year. He is now 1.6 m tall. How tall was he 1 year ago? 

Solution :

Height of Walt now = 1.6 m

Growing rate = 10 cm

100 cm = 1 m

10 cm = 0.1 m

Height of Walt 1 year ago = 1.6 - 0.1

= 1.5 m

Problem 5 :

Mary buys a reel of thread for sewing. There are 10 m of thread on the real. She uses 210 cm. How much is left on the reel in centimeters?

Solution :

Length of thread on the real = 10 m

She uses = 210 cm

1 m = 100 cm

Converting m to cm, we get 1000 cm

= 1000 - 210

= 790 cm

So, 790 cm of thread is left,

Problem 6 :

Mr. Martin's Spanish class is 45 minutes long. If it starts at 3:30, what time does it end?

Sebastian studies from 3:15 - 4:45. His sister, Sasha studies from 4:30 - 6:15. Who studied longer and by how much.

Solution :

Time spent by Martin :

Starting time Spanish class = 3 : 30

Duration of the class = 45 minutes

Ending time = 3 : 30 + 45

= 4 : 15

Time spent by Sebastian : 

= 4 : 45 - 3 :15

= 1 : 30

Time spent by Sasha :

= 4 : 30 - 6 :15

= 2 : 15

It is clear Sasha spent more time.

Problem 7 :

Peter is overweight. He is 105 kg. His aim is to lose 500 g per week. If he manages this, how many weeks will it be until he is 90 kg?

Solution :

Peter's weight now = 105 kg

He is wishing to reduce = 500 g per week

His target is to reach = 90 kg

difference between these two weights = 105 - 90

= 15 kg

Converting gram to kg, we get 500 / 1000 ==> (5/10) kg

Number of weeks he has to take = 15 / (5/10) 

= (15 x 10)/5

= 30 weeks

Problem 8 :

30 g serving of a certain breakfast cereal has 0.5 g of salt. How much salt would that be in milligrams

Solution :

10 mg = 1 gram

Converting gram to mg, we get

0.5 g = 0.5 x 10

= 5 mg

Problem 9 :

Chase measured a line for his art project. It is 200 millimeters long. How many centimeters is the line?

Solution :

10 mm = 1 cm

To convert mm to cm, we have to divide by 10.

200 mm = 200 / 10 cm

= 20 cm

Problem 10 :

Cheryl is moving to a new house. Her old house is 3 kilometers from her new house. How many meters is the old house from the new house?

Solution :

Distance between new house and old house = 3 km

1000 m = 1 km

To convert km to m, we have to multiply by 1000

3 km = 3000 m