2nd Class Mathematics Measurement Length, Weight and Capacity Measurement

Measurement

Measurement of Length

There are various units for the measurement of the length. These are metre, centimetres, kilometres etc. The standard unit for the measurement of the length is metre.

1 centimetre = 10 millimetres

1 metre = 100 centimetres

1 kilometre = 1000 metres

•           Example:

A rope is 45 centimetres long. What will be the length of the rope in millimetres?

(a) 450 millimetres                                              (b) 4500 millimetres

(c) 405 millimetres                                               (d) All the above

(e) None of these

Ans.     (a)

Explanation: 1 cm = 10 millimetres, 45 cm = 450 millimetres

•           Example:

What will be the length of each equal side of a triangle, if the sum of the length of its three sides is 15 cm?

(a) 4 cm                                                        (b) 5 cm

(c) 3 cm                                                        (d) All the above

(e) None of these

Ans.     (b)

Explanation: Each side = \[\frac{15}{3}\]= 5 cm.

Conversion Between Metre and Centimetre

1 metre = 1 \[\times \] 100 = 100 centimetre

2 metres = 2 \[\times \] 100 = 200 centimetres

100 metres = 100 \[\times \] 100 = 1000 centimetres

•           Example:

Convert 450 metres into centimetres.

(a) 45000 cm                                                     (b) 4500 m

(c) 2550 cm                                                       (d) All the above

(e) None of these               

Ans.     (a)

Explanation: 1 m = 100 cm

•           Example:

What will be the 10th part of a line segment of length 50 cm?

(a) 4 cm                                                           (b) 5 cm

(c) 2 cm                                                             (d) 3 cm

(e) None of these                

Ans.     (b)

Explanation: 10th part of 50 cm = \[\frac{50}{10}\]= 5 cm.

Conversion between Kilometre and Metre

1 kilometre = 1 \[\times \] 1000 = 1000 metres

2 kilometres = 2 \[\times \] 1000 = 2000 metres

100 kilometres = 100 \[\times \] 1000 = 100000 metres

•           Example:

Converts km 500 m in metres

(a) 8400 metres                                                  (b) 9500 metres

(c) 7900 metres                                                   (d) All the above

(e) None of these                

Ans.     (b)

Explanation: 9 km 500 m = (9 \[\times \] 1000 + 500) m = 9500 m. 

•           Example:

A travels a distance of 56 km and B travels a distance of 39 km. Who travels the longer distance and by how much?

(a) A by 17                                                     (b) A by 19 km

(c) B by 19 km                                                   (d) All the above

(e) None of these

Ans.     (a)

Explanation: Since 56 > 39 and 56 - 39 = 17, Therefore, A travels longer distance by 17 km.

Measurement of Masses

Mass is measured in grams and kilograms. Small masses are measured in milligram.

1 gram = 1 \[\times \] 1000 = 1000 milligrams

1000 grams = 1 kilogram

•           Example:

John bought the following items from the market: 3 kg 500 grams of potatoes, 4 kg 200 grams of onions and 2 kg 700 grams of green vegetables. What is the total weight of the items?

(a) 10 kg 400 grams                                            (b) 6 kg 300 grams

(c) 7 kg 100 grams                                              (d) All the above

(e) None of these

Ans.     (a)

Explanation: Total weight = 3 kg 500 grams + 4 kg 200 grams + 2 kg 700 grams = 9 kg 1400 grams = 10 kg 400 grams.

Measurement of Volume

The standard unit for the measurement of volume is litre. Volume of a liquid is measured in millilitres, litres and kilolitres,

1 litre = 1 \[\times \] 1000 = 1000 millilitres

2 litres = 2 \[\times \] 1000 = 2000 millilitres

1000 litres = 1 kilolitres

•          Example:

To obtain the volume of oil in litres how much quantity of oil is required in a container, which already contains 45 litres 900 millilitres of oil?                

(a) 500 ml                                                          (b) 100 ml

(c) 600 ml                                                          (d) All the above

(e) None of these

Ans.     (b)

Explanation: 45 litres 900 millilitres of oil becomes 46 litres when 100 millilitres is added to it.