RBSE Solutions for Class 6 Maths Chapter 8 Decimals Ex 8.4

Rajasthan Board RBSE Solutions for Class 6 Maths Chapter 8 Decimals Ex 8.4 Textbook Exercise Questions and Answers.

RBSE Class 6 Maths Solutions 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) 725paise
Answer:
(a) 5 paise
1 paisa = ₹ \(\frac{1}{100}\)
∴ 5paise = \(\frac{1}{100}\) × 5 = ₹ 0.05

(b) 75 paise
1 paisa = ₹ \(\frac{1}{100}\)
75 paise = ₹ \(\frac{1}{100}\) × 75 = ₹ 0.75

(c) 20 paise
1 paisa = ₹ \(\frac{1}{100}\)
20 paise = \(\frac{1}{100}\) × 20 = ₹ 0.20

(d) 50 rupees 90 paise
1 paisa = ₹ \(\frac{1}{100}\)
90 paise = \(\frac{1}{100}\) × 90 = = ₹ 0.90
∴ 50 rupees 90 paise
= 50 rupees + 0.90 rupee = 50.90 rupees

(e) 725 paise 
1 paisa = ₹ \(\frac{1}{100}\)
∴ 725 paise = \(\frac{1}{100}\) × 725
= \(\frac{725}{100}\) = 7.25

Question 2.
Express as metre using decimals:
(a) 15 cm
(b) 6 cm
(c) 2 m 45 cm
(d) 9 m 7 cm
(e) 419 cm
Answer:
(a) 15 cm
∵ 1 cm = \(\frac{1}{100}\) m
∴ 15 cm = \(\frac{1}{100}\) × 15 = 0.15 m

(b) 6 cm
∵ 1 cm = \(\frac{1}{100}\) m
∴ 6 cm = \(\frac{1}{100}\) × 6 = \(\frac{6}{100}\) = 0.06 m

(c) 2 m 45 cm = 2 m + 45 cm
= 2 + \(\frac{1}{100}\) × 45
= 2 + \(\frac{45}{100}\)
= 2 + 0.45
= 2.45 m

(d) 9 m 7 cm = 9 m + 7 cm
= 9 + \(\frac{7}{100} \)
= 9+ 0.07 = 9.07 m

(e) 419 cm
∵ 1 cm = \(\frac{1}{100}\) m
∴ 419 cm = \(\frac{1}{100}\) × 419 = \(\frac{419}{100} \)
= 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) 5 mm
∵ 1 mm = \(\frac{1}{10}\) cm
∴ 5 mm = \(\frac{1}{10}\) × 5 = 0.5 cm

(b) 60 mm
∵ 1 mm = \(\frac{1}{10}\) cm
∴ 60 mm = \(\frac{1}{10}\) × 60 = \(\frac{60}{10}\) = 6.0 cm

(c) 164.mm
∵ 1 mm = \(\frac{1}{10}\) cm
∴ 164 mm = 160 mm + 4 mm
= \(\frac{160}{10}\)cm + \(\frac{4}{10}\)cm
= 16 cm + 0.4 cm = 16.4 cm 

(d) 9 cm 8 mm = 9 cm + 8 mm
= 9 cm + \(\frac{1}{10}\) × 8 cm
= 9 cm + \(\frac{8}{10}\) cm = 9.8 cm

(e) 93 mm
∵ 1 mm = \(\frac{1}{10}\) cm
93 mm = \(\frac{1}{10}\) × 93 = \(\frac{93}{10}\) = 9.3 cm

Question 4.
Express
(a) 8 m
Answer:
∵ 1 Km = 1000 m
∴ 1 m = \(\frac{1}{1000}\) km
∴ 8 m = \(\frac{1}{1000}\) × 8 = \(\frac{8}{1000}\)
= 0.008 km

(b) 88 m
Answer:
∵ 1 Km = 1000 m
∴ 1 m = \(\frac{1}{1000}\) km
∴ 88 m = \(\frac{1}{1000}\) × 88 = \(\frac{88}{1000}\)
= 0.088 km

(c) 8888 m
Answer:
∵ 1 Km = 1000 m
∴ 1 m = \(\frac{1}{1000}\) km
∴ 8888 m = \(\frac{1}{1000}\) × 8888 = \(\frac{8888}{1000}\)
= 8.888 km

(d) 70 km 5 m
Answer:
∴ 1 m = \(\frac{1}{1000}\) km
∴ 5 m = \(\frac{1}{1000}\) × 5 = \(\frac{5}{1000}\)
= 0.005 km

∴ 70 km 5m = 70 + 0.005 km
= 70.005 km

Question 5.
Express as kg using decimals :
(a) 2 g
(b) 100g
(c) 3750 g
(d) 5 kg 8 g
(e) 26 kg 50 g
Answer:
(a) 2 g 
∵ 1 kg = 1000 g
∴ 1 g = \(\frac{1}{1000}\)kg
and 2 g = \(\frac{1}{1000}\) × 2 = 0.002 kg

(b) 100 g
1g = \(\frac{1}{1000}\)kg
∴ 100 g = \(\frac{1}{1000}\) × 100 = 01 kg

(c) 3750 g .
∴ 1 g = \(\frac{1}{1000}\)kg
∴ 3750 g = \(\frac{1}{1000}\) × 3750 = 3750 kg

(d) 5 kg 8 g
∴ 1 g = \(\frac{1}{1000}\)kg
8 g = \(\frac{1}{1000}\) × 8 kg = 0 008 kg 
5 kg 8 g = 5 kg + 0.008 kg 
= 5.008 kg

(e) 26 kg 50 g
∴ 1 g = \(\frac{1}{1000}\)kg
50g = \(\frac{1}{1000}\) × 50g = \(\frac{50}{1000}\) kg
= 0.050 kg
∴ 26 kg 50 g = 26 + 0.050 
= 26.050 kg