Exercise 2.5
1 Which one is greater?
(i)
0.7 or 0.07
Sol:
Therefore, 0.7
(ii)
7 or 8.5
Sol:
Therefore, 7
(iii)
1.47 or 1.51
Sol:
Therefore, 1.47
(iv)
6 or 0.66
Sol:
Therefore, 6
2 Express the following as rupees using decimals
(i)
9 paise
Sol:
Since 100 paise = 1 rupee
Therefore, 9 paise =
(ii)
77 rupees 7 paise
Sol:
We know 7 paise =
So, 77 rupees 7 paise =
(iii)
235 paise
Sol:
Since 100 paise = 1 rupee
Therefore, 235 paise =
3
(i)
Express 10 cm in metre and kilometre
Sol:
Centimeters to meters: 1 meter = 100 centimeters
Therefore,
So,
Meters to kilometers: 1 kilometer = 1000 meters
(ii)
Express 45 mm in centimeter, meter and kilometer
Sol:
Millimeters to centimeters: 1 centimeter = 10 millimeters
So,
Centimeters to meters:
Meters to kilometers:
4 Express the following in kilograms.
(i)
190 g
Sol:
Since 1 kilogram (kg) = 1000 grams (g)
Therefore,
(ii)
247 g
Sol:
(iii)
44 kg 80 gm
Sol:
So, 44 kg 80 g =
5 Write the following decimal numbers in expanded form.
(i)
55.5
Sol:
= 50 + 5 +
(ii)
5.55
Sol:
= 5 + 5/10 +
(iii)
303.03
Sol:
= 300 + 3 +
(iv)
30.303
Sol:
= 30 + 3/10 +
(v)
1234.56
Sol:
= 1000 + 200 + 30 + 4 + 5/10 +
6 Write the place value of 3 in the following decimal numbers.
(i)
3.46
Sol:
The place value of 3 is in ones place
Therefore, place value =
(ii)
32.46
Sol:
The place value of 3 is in tens place
Therefore, place value =
=
(iii)
7.43
Sol:
The place value of 3 is in hundredths place
Therefore, place value =
=
(iv)
90.30
Sol:
The place value of 3 is in tenths place
Therefore, place value =
=
(v)
794.037
Sol:
The place value of 3 is in hundredths place
Therefore, place value =
=
7 Aruna and Radha start their journey from two different places A and E. Aruna chose the path from A to B then to C, while Radha chose the path from E to D then to C. Find who travelled more and by how much?
img(src="/content/scert/7/fractions_and_decimals/images/chapter2/exercise5/q7.png" width=100 height=100)
Sol:
Aruna's Path (A to B to C): A to B =
Total distance for Aruna:
Radha's Path (E to D to C): E to D =
Total distance for Radha:
Difference in distance:
Therefore, Radha traveled 0.10 km or 100 meters more than Aruna.
8 Upendra went to the market to buy vegetables. He brought 2 kg 250 gm tomatoes, 2 kg 500 gm potatoes, 750 gm lady fingers and 1125 gm green chillies. How much weight did Upendra carry back to his house?
Sol:
Converting all weights to kilograms:
Tomatoes: 2 kg 250 gm =
Potatoes: 2 kg 500 gm =
Lady fingers: 750 gm =
Green chillies: 1125 gm =
Total weight: