# GSEB Solutions Class 6 Maths Chapter 8 Decimals Ex 8.4

Gujarat Board GSEB Textbook Solutions Class 6 Maths Chapter 8 Decimals Ex 8.4 Textbook Questions and Answers.

## Gujarat Board Textbook Solutions 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
Solution:
(a) 5 paise
∵ 1 paisa = ₹ $$\frac { 1 }{ 100 }$$
∴ 5 paise = ₹ 5 × $$\frac { 1 }{ 100 }$$ = ₹ $$\frac { 5 }{ 100 }$$ = ₹ 0.05

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

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

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

(e) 725 paise
∵ 1 paisa = ₹ $$\frac { 1 }{ 100 }$$
∴ 725 paise = ₹ 725 × $$\frac { 1 }{ 100 }$$ = ₹ $$\frac { 725 }{ 100 }$$
= ₹ [7 + 0.25] = ₹ 7.25

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

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

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

(d) 9 m 7 cm
∵ 1 cm = $$\frac { 1 }{ 100 }$$ m
∴ 9 m 7 cm = 9 m + 7 cm
9 m + 7 cm = 9 m + 7 × $$\frac { 1 }{ 100 }$$ m
= 9 m + 0.07 m
9 m 7 cm = (9 + 0.07)m = 9.07 m

(e) 419 cm
∵ 1 cm = $$\frac { 1 }{ 100 }$$ m
∴ 419 cm = 419 × $$\frac { 1 }{ 100 }$$ m = $$\frac { 419 }{ 100 }$$ m
= $$\left(\frac{400}{100}+\frac{19}{100}\right)$$ m = $$\left(4+\frac{19}{100}\right)$$ m
= (4 + 0.19) m = 4.19 m

Question 3.
(a) 5 mm
(b) 60 mm
(c) 164 mm
(d) 9 cm 8 mm
(e) 93 mm
Solution:
(a) 5 mm
∵ 1 mm = $$\frac { 1 }{ 10 }$$ cm
∴ 5 mm = 5 × $$\frac { 1 }{ 10 }$$ cm = $$\frac { 5 }{ 10 }$$ cm = 0.5 cm

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

(c) 164 mm
∵ 1 mm = $$\frac { 1 }{ 10 }$$ cm
∴ 164 mm = 164 × $$\frac { 1 }{ 10 }$$ cm = $$\frac { 164 }{ 10 }$$ cm
= $$\left(\frac{100+60+4}{10}\right)$$ cm = $$\left(\frac{100}{10}+\frac{60}{10}+\frac{4}{10}\right)$$ cm
= $$\left(10+6+\frac{4}{10}\right)$$ cm = 16.4 cm

(d) 9 cm 8 mm
∵ 1 mm = $$\frac { 1 }{ 10 }$$ cm and 9 cm 8 mm = 9 cm 8 mm
∴ 9 cm 8 mm = 9 cm + 8 × $$\frac { 1 }{ 10 }$$ cm
= 9 cm + 0.8 cm
= (9 + 0.8) cm = 9.8 cm

(e) 93 mm
∵ 1 mm = $$\frac { 1 }{ 10 }$$ cm
∴ 93 mm = 93 × $$\frac { 1 }{ 10 }$$ cm
= $$\frac { 93 }{ 10 }$$ cm = $$\left(\frac{90}{10}+\frac{3}{10}\right)$$ cm
= (9 + 0.3) cm = 9.3 cm

Question 4.
Express as km using decimals.
(a) 8 m
(b) 88 m
(c) 8888 m
(d) 70 km 5 m
Solution:
(a) 8 m
∵ 1000 m = 1 m
∴ 1 m = $$\frac { 1 }{ 1000 }$$ km
Now, 8 m = 8 × $$\frac { 1 }{ 1000 }$$ km
= $$\frac { 8 }{ 1000 }$$ km = 0.008 km

(b) 88 m
∵ 1000 m = 1 m
∴ 1 m = $$\frac { 1 }{ 1000 }$$ km
Now, 8 m = 88 × $$\frac { 1 }{ 1000 }$$ km
= $$\frac { 88 }{ 1000 }$$ km = 0.088 km

(c) 8888 m
∵ 1 m = $$\frac { 1 }{ 1000 }$$ km
∴ 8888 m = 8888 × $$\frac { 1 }{ 1000 }$$ km = $$\frac { 8888 }{ 1000 }$$ km
= $$\left[\frac{8000+888}{1000}\right]$$ km = $$\left[\frac{8000}{1000}+\frac{888}{1000}\right]$$ km
= [8 + 0.888] km = 8.888 km

(d) 70 km 5 m
∵ 1 m = $$\frac { 1 }{ 1000 }$$ km and 70 km 5 m = 70 km + 5 m
∴ 70 km 5 m = 70 km + 5 × $$\frac { 1 }{ 1000 }$$ km
= $$\left[70+\frac{5}{1000}\right]$$ km
= [70 + 0.005] km = 70.005 km

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

(b) 100 g
∵ 1 g = $$\frac { 1 }{ 1000 }$$ kg
∴ 100 g = $$\frac { 1 }{ 1000 }$$ kg
= $$\frac { 1 }{ 1000 }$$ kg × 100 kg = 0.1 kg

(c) 3750 g
∵ 1 g = $$\frac { 1 }{ 1000 }$$ kg
∴ 3750 g = 3750 × $$\frac { 1 }{ 1000 }$$ kg
= $$\frac { 3750 }{ 1000 }$$ kg
= $$\left(\frac{3000+750}{1000}\right)$$ kg = $$\left(\frac{3000}{1000}+\frac{750}{1000}\right)$$ kg
= (3 + 0.750) kg = 3.750 kg

(d) 5 kg 8 g
∵ 1 g = $$\frac { 1 }{ 1000 }$$ kg and 5 kg 8 g = 5 kg + 8 g
∴ 5 kg 8 g = 5 kg + 8 × $$\frac { 1 }{ 1000 }$$ kg
= $$\left(5+\frac{8}{1000}\right)$$ kg
= (5 + 0.008) kg = 5.008 kg

(e) 26 kg 50 g
∵ 1 g = $$\frac { 1 }{ 1000 }$$ kg and 26 kg 50 g = 26 kg + 50 g
∴ 26 kg 50 g = 26 kg + 50 × $$\frac { 1 }{ 1000 }$$ kg
= 26 kg + $$\frac { 50 }{ 1000 }$$ kg = $$\left(26+\frac{50}{1000}\right)$$ kg
= (26 + 0.050) kg = 26.050 kg