RD Sharma Solutions Class 6 Knowing Our Numbers Exercise 1.7

RD Sharma Solutions Class 6 Chapter 1 Exercise 1.7

RD Sharma Class 6 Solutions Chapter 1 Ex 1.7 PDF Download

Exercise 1.7

Q1. Estimate the following by rounding off each factor to nearest hundreds:

i) 730 + 998

ii) 796 – 314

iii) 875 – 384

Sol :

i) 700 + 1000 = 1700

ii) 800 – 300 = 500

iii) 900 – 400 = 500

Q2. Estimate the following by rounding off each factor to nearest thousands:

i) 12904 + 2888

ii) 28292 – 21496

Sol :

i) 13000 + 3000 = 16000

ii) 28000 – 21000 = 7000

Q3. Estimate the following by rounding off each number to its greatest place:

i) 439 + 334 + 4317

ii) 8325 – 491

iii) 108734 – 47599

iv) 898 x 785

v) 9 x 795

vi) 87 x 317

Sol :

i) 400 + 300 + 4000 = 4700

ii)8000 – 500 = 7500

iii)100000 -500000 = 50000

iv) 900 x 800 = 720000

v) 10 x 800 = 8000

vi) 90 x 300 = 27000

Q4. Find the estimated quotient for each of the following by rounding off each number to its greatest place :

i) \(878 \div 28\)

ii) \(745 \div 24\)

iii) \(4489 \div 394\)

Sol :

i) \(900 \div 30\) = 30

ii) \(700 \div 20\) = 35

iii) \(4000 \div 400\) = 10

Exercise 1.8

Q1. Write the expression for each of the following statements using brackets :

i) Four multiplied by the sum of 13 and 7

ii) Eight multiplied by the difference of four from nine.

iii) Divide the difference of twenty eight and seven by 3.

The sum of 3 and 7 in multiplied by the difference of twelve and eight.

Sol :

i)4 x ( 13 + 7 )

ii)8 x ( 9 – 4 )

iii)\(\frac{28 – 7 }{ 3 }\)

iv) ( 3 + 7 ) x ( 12 – 8 )

Q2. Simplify each of the following :

i)124 – ( 12 – 2 ) x 9

ii) ( 13 + 7 ) x ( 9 – 4 ) – 18

iii) 210 – ( 14 – 4 ) x ( 18 + 2 ) – 10

Sol :

i) 34

ii) 82

iii) 0

Exercise 1.9

Q1) Simplify each of the following :

i) 7 x 109

ii) 6 x 112

iii) 9 x 105

iv) 17 x 109

v) 16 x 108

vi) 12 x 105

vii) 102 x 103

viii) 101 x 105

ix) 109 x 107

Sol :

i) 763

ii) 672

iii) 945

iv) 1853

v) 1728

vi) 1260

vii) 10506

viii)10605

ix)11663

Exercise 1.10

Q1) Write the roman – numerals for each of the following:

i) 33

ii) 48

iii) 76

iv) 95

Sol :

i) XXXIII

ii) XLVIII

iii) LXXVI

iv) XCV

Q2) Write the following in roman numerals:

i) 154

ii) 173

iii) 248

iv) 319

SOL :

i) CLIV

ii) CLXXIII

iii) CCXLVIII

iv) CCCXIX

Q3) Write the following in roman numerals:

i) 1008

ii) 2718

iii) 3906

iv) 3794

SOL :

i) KVIII

ii) KKDCCXVIII

iii) KKKCKVI

iv) KKKDCCXCIV

Q4) Write the following in roman numerals :

i) 4201

ii) 10009

iii) 44000

iv) 25819

SOL :

i) \(\bar{IV}CCI\)

ii) \(\bar{X}IX\)

iii) \(\bar{ XLIV }\)

iv) \(\bar{XXV}DCCCXIX\)

Q5) Write the following in Hindu – Arabic numerical:

i) XXVI

ii) XXIX

iii) LXXII

iv) XCI

SOL :

i) 26

ii) 29

iii) 72

iv) 91

Q6) Write the corresponding Hindu – Arabic numerical for each of the following :

i) CIX

ii) CLXXII

iii) CCLIV

iv) CCCXXIX

SOL :

i) 109

ii) 172

iii) 254

iv) 329

Q7) Write the corresponding Hindu – Arabic numerical for each of the following :

i) KXIX

ii) KDLXV

iii) KKCXXIII

iv) KKKDCXL

SOL :

i) 1019

ii) 1565

iii) 2123

iv) 3640

Q8)Write the following in Hindu – Arabic numerical :

i) \(\bar{IV}CDXLIV\)

ii) \(\bar{VI}CKXLIX\)

iii) \(\bar{IX}CCCXCI\)

iv) \(\bar{LX}XIX\)

SOL :

i) 4444

ii) 6949

iii) 9391

iv) 70009

Q9) Which of the following is meaningless ?

i) \(\bar{III}CC\)<

ii) KKKCCXI

iii) XD

iv) VC

SOL : (i) and (iii) are meaningless.