These NCERT Solutions for Class 6 Maths Chapter 8 Decimals Ex 8.4 Questions and Answers are prepared by our highly skilled subject experts.
NCERT Solutions for Class 6 Maths Chapter 8 Decimals Ex 8.4
Question 1.
Express as rupees using decimals:
(a) 5 paise
(b) 75 paise
(c) 20 paise
(d) 50 rupees 90 paise
(e) 725 paise
Answer:
(a) ∵ 1 paisa = ₹ \(\frac { 1 }{ 100 }\)
∴ 5 paise = \(\frac { 1 }{ 100 }\) × 5 = ₹ 0.05
(b) ∵ 1 paisa = \(\frac { 1 }{ 100 }\)
∴ 75 paise = \(\frac { 1 }{ 100 }\) × 75 = ₹ 0.75
(c) ∵ 1 paisa = X \(\frac { 1 }{ 100 }\)
∴ 20 paise = \(\frac { 1 }{ 100 }\) × 20 = ₹ 0.2
(d) ∵ 1 paisa = X \(\frac { 1 }{ 100 }\)
∴ ₹ 50 + 90 paise
= 50 + \(\frac { 1 }{ 100 }\) × 90 = ₹ 50.90
(e) ∵ 1 paisa = ₹ \(\frac { 1 }{ 100 }\)
∴ 725 paise = \(\frac { 1 }{ 100 }\) × 725
= ₹ 7.25
Question 2.
Express as metres using decimals:
(a) 15 cm
(b) 6 cm
(c) 2 m 45 cm
(d) 9 m 7 cm
(e) 419 cm
Answer:
(a) ∵ 1 cm = \(\frac { 1 }{ 100 }\) m
∴ 15 cm = \(\frac { 1 }{ 100 }\) × 15 = 0.15 m 100
(b) ∵ 1 cm = \(\frac { 1 }{ 100 }\) m
∴ 6 cm = \(\frac { 1 }{ 100 }\) × 6 = 0.06 m
(c) ∵ 1 cm = \(\frac { 1 }{ 100 }\) m
∴ 2 m 45 cm = 2 + \(\frac { 1 }{ 100 }\) × 45
= 2.45 m
(d) ∵ 1 cm = \(\frac { 1 }{ 100 }\) m
∴ 9 m 7 cm = 9 x \(\frac { 1 }{ 100 }\) × 9 = 9.07 m
(e) ∵ 1 cm = \(\frac { 1 }{ 100 }\) m
∴ 419 = \(\frac { 1 }{ 100 }\) × 419 = 4.19 m
Question 3.
Express as cm using decimals:
(a) 5 mm
(b) 60 mm
(c) 164 mm
(d) 9 cm 8 mm
(e) 93 mm
Answer:
(a) ∵ 1mm = \(\frac { 1 }{ 10 }\) cm
5mm = \(\frac { 1 }{ 10 }\) × 5 = 0.5 cm
(b) ∵ 1 mm = \(\frac { 1 }{ 10 }\) cm 10
∴ 60 mm = \(\frac { 1 }{ 10 }\) × 60 = 6 cm
(c) ∵ 1 mm = \(\frac { 1 }{ 10 }\) cm
∴ 164 mm = \(\frac { 1 }{ 10 }\) × 164 = 16.4 cm
(d) ∵ 1 mm = \(\frac { 1 }{ 10 }\) cm
∴ 9 cm 8 mm = 9 + \(\frac { 1 }{ 10 }\) × 8
= 9 + 0.8 cm = 9.8 cm
(e) ∵ 1 mm = \(\frac { 1 }{ 10 }\) cm
∴ 93 mm = \(\frac { 1 }{ 10 }\) × 93 cm
Question 4.
Express as km using decimals:
(a) 8m
(b) 88 m
(c) 8888 m
(d) 70 km 5 m
Answer:
(a) ∵ 1 m = \(\frac { 1 }{ 1000 }\) km
∴ 8m = \(\frac { 1 }{ 1000 }\) × 8 = 0.008 km
(b) ∵ 1 m = \(\frac { 1 }{ 1000 }\) km
∴ 88 m: 1 \(\frac { 1 }{ 1000 }\) × 88 = 0.088 km
(c) ∵ 1 m = \(\frac { 1 }{ 1000 }\) km
∴ 8888m = \(\frac { 1 }{ 1000 }\) × 88 = 8.888km
(d) ∵ 1m = \(\frac{1}{100}\)km
∴ 70km 5m = 70 + \(\frac{1}{100}\) × 5
= 70.005 km
Question 5.
Express as kg using decimals:
(a) 2g
(b) 100g
(c) 3750 g
(d) 5 kg 8 g
(e) 26kg 50g
Answer:
(a) 1 g = \(\frac{1}{1000}\) kg
∴ 2g = \(\frac{1}{1000}\) × 2 = 0.002kg
(b) ∵ 1g = \(\frac{1}{1000}\) kg
∴ 100g= \(\frac{1}{1000}\) × 100 = 0.1 kg
(c) ∵ 1g = \(\frac{1}{1000}\) kg
∴ 3750g = \(\frac{1}{1000}\) × 3750 = 3.750kg
(d) ∵ 1g = \(\frac{1}{1000}\) kg
∴ 5kg50g = 5 + \(\frac{1}{1000}\) × 8
= 5.008kg
(e) ∵ 1g = \(\frac{1}{1000}\) kg
∴ 26kg 50g = 26 + \(\frac{1}{1000}\) × 50
= 26.050kg