Decimals Ex-8.4

NCERT solutions for Maths Decimals 

NCERT Solutions for Class 6 Maths Decimals

Class –VI Mathematics

(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) $\because$ 1 paisa = Rs.$\frac{1}{{100}}$

(b) $\because$ 1 paisa = Rs.$\frac{1}{{100}}$

$\therefore$ 5 paise = $\frac{1}{{100}}$ x 5 = Rs. 0.05

$\therefore$ 75 paise = $\frac{1}{{100}}$ x 5 = Rs. 0.75

(c) $\because$ 1 paisa = Rs.$\frac{1}{{100}}$

(d) $\because$ 1 paisa = Rs.$\frac{1}{{100}}$

$\therefore$ 20 paise = $\frac{1}{{100}}$ x 5 = Rs. 0.05

$\therefore$Rs. 50 + 90 paise = 50 +$\frac{1}{{100}}$ x 90 = Rs. 50.90

(e) $\because$ 1 paisa = Rs.$\frac{1}{{100}}$

$\therefore$ 725 paise = $\frac{1}{{100}}$ x 725 $= \frac{{725}}{{100}}$ = Rs. 7.25

Question 2.Express as meters using decimals:

(a) 15 cm

(b) 6 cm

(c) 2 m 45 cm

(d) 9 m 7 cm

(e) 419 cm

Answer:

(a) $\because$ 1 cm = $\frac{1}{{100}}$ m

(b) $\because$ 1 cm = $\frac{1}{{100}}$ m

$\therefore$ 15 cm = $\frac{1}{{100}}$ x 15 = 0.15 m

$\therefore$ 6 cm = $\frac{1}{{100}}$ x 6 = 0.06 m

(c) $\because$ 1 cm = $\frac{1}{{100}}$ m

(d) $\because$ 1 cm = $\frac{1}{{100}}$ m

$\therefore$ 2 m 45 cm = 2 + $\frac{1}{{100}}$ x 45 = 2.45 m

$\therefore$ 9 m 7 cm = 9 +$\frac{1}{{100}}$ x 7 = 9.07 m

(e) $\because$ 1 cm = $\frac{1}{{100}}$ m

$\therefore$ 419 cm = $\frac{1}{{100}}$ x 419 = $\frac{{419}}{{100}} =$ 4.19 m

NCERT Solutions for Class 6 Maths Exercise 8.4

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) $\because$ 1 mm = $\frac{1}{{10}}$ cm

(b) $\because$ 1 mm = $\frac{1}{{10}}$ cm

$\therefore$ 5 mm = $\frac{1}{{10}}$ x 5 = 0.5 cm

$\therefore$ 60 mm = $\frac{1}{{10}}$ x 60 = 6 cm

(c) $\because$ 1 mm = $\frac{1}{{10}}$ cm

(d) $\because$ 1 mm = $\frac{1}{{10}}$ cm

$\therefore$ 164 mm = $\frac{1}{{10}}$ x 164 = 16.4 cm

$\therefore$ 9 cm 8 mm = 9 + $\frac{1}{{10}}$ x 8 = 9 + 0.8 = 9.8 cm

(e) $\because$ 1 mm = $\frac{1}{{10}}$ cm

$\therefore$ 93 mm = $\frac{1}{{10}}$ x 93 = 9.3 cm

Question 4.Express as km using decimals:

(a) 8 m

(b) 88 m

(c) 8888 m

(d) 70 km 5 m

Answer:

(a) $\because$ 1 m = $\frac{1}{{1000}}$ km

(b) $\because$ 1 m = $\frac{1}{{1000}}$ km

$\therefore$ 8 m = $\frac{1}{{1000}}$ x 8 = 0.008 km

$\therefore$ 88 m = $\frac{1}{{1000}}$ x 88 = 0.088 km

(c) $\because$ 1 m = $\frac{1}{{1000}}$ km

(d) $\because$ 1 m = $\frac{1}{{1000}}$ km

$\therefore$ 8888 m = $\frac{1}{{1000}}$ x 8888 = 8.888 km

$\therefore$ 70 km 5 m = 70 + $\frac{1}{{1000}}$ x 5 = 70.005 km

NCERT Solutions for Class 6 Maths Exercise 8.4

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

Answer:

(a) $\because$ 1 g = $\frac{1}{{1000}}$ kg

(b) $\because$ 1 g = $\frac{1}{{1000}}$ kg

$\therefore$ 2 g = $\frac{1}{{1000}}$ x 2 = 0.002 kg

$\therefore$ 100 g = $\frac{1}{{1000}}$ x 100 = 0.1 kg

(c) $\because$ 1 g = $\frac{1}{{1000}}$ kg

(d) $\because$ 1 g = $\frac{1}{{1000}}$ kg

$\therefore$ 3750 g = $\frac{1}{{1000}}$ x 3750 = 3.750 kg $\therefore$ 5 kg 8 g = 5 +$\frac{1}{{1000}}$ x 8 = 5.008 kg

(e) $\because$ 1 g = $\frac{1}{{1000}}$ kg

$\therefore$ 26 kg 50 g = 26 +$\frac{1}{{1000}}$ x 50 = 26.050 kg