Std 6 General Science · Chapter 2

2. Measurement

Complete solutions to the Exercises. Maharashtra State Board (Balbharati), Grade Six General Science.

About the chapter

This chapter explains why we need measurement. It tells us about standard and non-standard units. We learn to measure length with a ruler and a measuring tape. We also learn to measure temperature with different thermometers.

Key points

A hand span or a footstep is a non-standard unit. It differs from person to person.
Standard units give the same result for everyone.
The SI unit of length is the metre. The SI unit of temperature is the kelvin.
1 km = 1000 m, 1 m = 100 cm and 1 cm = 10 mm.
The normal temperature of the human body is 37°C.
Clinical, digital, infrared and laboratory thermometers are used for different purposes.

Words to remember

measurement – comparing a quantity with a fixed unit
standard unit – a unit that is the same everywhere
SI unit – a unit accepted all over the world
reference point – the fixed point from which a distance is measured
thermometer – an instrument used to measure temperature

Exercises

1Suggest appropriate words for the following blanks.

(1) The instrument used for measuring temperature is called a thermometer.

(2) The normal temperature of the human body is 37°C.

(3) When measuring distance from a fixed point, that point is called the reference point.

(4) 1 Metre = 100 Centimetres.

(5) In the glass bulb of a thermometer, coloured alcohol is filled.

(6) The SI unit of temperature is kelvin (K).

2Which instrument will you use for the following measurements? State the name of the appropriate instrument.

Length of a pencil or pen – 15 cm ruler
Your own height – measuring tape
Girth of a large tree trunk – flexible measuring tape (tailor’s tape)
Thickness of an eraser – vernier caliper

3Find my pair.

Group A	Group B
(1) SI unit of length	(c) Metre
(2) Unit of temperature used in research experiments	(d) Kelvin
(3) Measurement using a hand span	(b) Non-standard method of length measurement
(4) Red coloured liquid in thermometer	(a) Alcohol

4Write whether the following statements are true or false.

(a) 1 km = 100 cm

False. 1 km = 1,00,000 cm.

(b) If a ruler and a measuring tape are used to measure length, the length of the table will be different.

False. Both give the same length. Both use standard units.

False. A laboratory thermometer is used for boiling water.

(d) Errors in observation can lead to mistakes while recording temperature.

True.

(e) The accurate temperature of an object can be told just by touching it.

False. Only a thermometer can tell the accurate temperature.

5Arrange the following units in the correct order from biggest to smallest. (a) 1 cm. (b) 1 km. (c) 1 mm. (d) 1 m.

(b) 1 km > (d) 1 m > (a) 1 cm > (c) 1 mm

1 km = 1000 m, 1 m = 100 cm and 1 cm = 10 mm.

6What is the smallest length that can be measured using a ruler from a compass box?

The smallest length is 1 millimetre (0.1 cm).

Each centimetre on the ruler is divided into 10 millimetres.

Each centimetre on the ruler has 10 equal parts. Each part is 1 mm.

7Which unit will you use while measuring the following?

Length of a book – centimetre (cm)
Thickness of a key – millimetre (mm)
Distance between Nagpur and Mumbai – kilometre (km)
Length of a cloth – metre (m)

8Why there is a need of standard measurement tools?

Body parts like the hand span or footstep differ from person to person.
So non-standard units give different results.
Standard tools give the same measurement to everyone.
They make buying and selling fair.
Scientists all over the world can compare their results.

9Obtain information about the measurements used in earlier days in your area to measure distance, weight and volume.

Ask the elders in your area. Some old units used in Maharashtra were:

Distance: angul, vit (hand span), hat (cubit), kos
Weight: tola, sher, man
Volume: payali, adholi, shere

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