Decimals

Exercise 2.5

Question 1: Which is greater?

  1. 0.5 or 0.005

    Answer: 0.5 > 0.005
  2. 0.7 or 0.5

    Answer: 0.7 > 0.5
  3. 7 or 0.7

    Answer: 7 > 0.7
  4. 1.37 or 1.49

    Answer: 1.49 > 1.37
  5. 2.03 or 2.30

    Answer: 2.30 > 2.03
  6. 0.8 or 0.88

    Answer: 0.88 > 0.8

Question 2: Express as rupees using decimals:

(a) 7 paise

Answer: `7 paise = 7xx(1)/(100)=Rs. 0.07`

(b) 7 rupees 7 paise

Answer: `Rs. 7+7p=Rs. 7 + Rs. 7xx(1)/(100)`

`=Rs. 7+Rs. 0.07= Rs. 7.07`

(c) 77 rupees 77 paise

Answer: `Rs. 77 + 77p = Rs. 77+Rs. 77xx(1)/(100)`

`=Rs. 77+Rs. 0.77=Rs. 77.77`

(d) 50 paise

Answer: `50p=Rs. 50xx(1)/(100)=Rs. 0.5`

(e) 235 paise

Answer: `235p=Rs. 235xx(1)/(100)=Rs. 2.35`


Question 3: (i) Express 5 cm in metre and kilometer (ii) Express 35 mm in cm, m and km.

Answer: `5 cm = 5xx(1)/(100)m=0.05m`

`5 cm = 5xx(1)/(100000)km`

`=0.00005 km`

Question 4: Express the following in kilogram:

(a) 200 g

Answer: `200 g = (200)/(1000)kg=0.2kg`

(b) 3470 g

Answer: `3470g=(3470)/(1000)kg=3.47kg`

(c) 4 kg 8 g

Answer: `4kg+8g=4kg+(8)/(1000)kg`

`=4kg+0.008kg=4.008kg`


Question 5: Write the following decimal numbers in expanded form:

(a) 20.03

Answer: `2xx10+(3)/(100)`

(b) 2.03

Answer: `2xx1+(3)/(100)`

(c) 200.03

Answer: `2xx100+(3)/(100)`

(d) 2.034

Answer: `2xx1+(3)/(100)+(4)/(1000)`

Question 6: Write the place value of 2 in the following decimal numbers:

  1. 2.56

    Answer: One
  2. 21.37

    Answer: Ten
  3. 10.25

    Answer: One tenth
  4. 9.42

    Answer: One hundredth
  5. 63.352

    Answer: One thousandth

Question 7: Dinesh went from place A to place B and from there to place C. A is 7.5 km from B and B is 12.7 km from C. Ayub went from place A to place D and from there to place C. D is 9.3 km from A and C is 11.8 km from D. Who travelled more and by how much?

fraction for question

Answer: Distance travelled by Dinesh `= 7.5 km + 12.7 km = 20.2 km`
Distance travelled by Ayub `= 9.3 km + 11.8 km = 21.1 km`
Now, `21.1 km – 20.2 km = 0.9 km`
Ayub travelled more by 0.9 km or 900 m

Question 8: Shyama bought 5 kg 300g apples and 3 kg 250 g mangoes. Sarala bought 4 kg 800 g oranges and 4 kg 150 g bananas. Who bought more fruits?

Answer: Total weight of fruits bought by Shyama `= 5.30 kg + 3.25 kg = 8.55 kg`
Total weight of fruits bought by Sarala `= 4.80 kg + 4.15 kg = 8.95 kg`
Now, `8.95 kg – 8.55 kg = 0.40 kg`
Sarala bought 400 g more fruits than Shyama.

Question 9: How much less is 28 km than 42.6 km?

Answer: `42.6 – 28 = 14.6` km



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