1Book Back Questions88 questions
Q.1The smallest 7 digit number is _______v
Q.2The largest 8 digit number is _______v
Q.3The place value of 5 in 7005380 is ________v
Q.4The expanded form of the number 76,70,905 is _______v
Answer:7 × 10,00,000 + 6 × 1,00,000 + 7 × 10,000 + 0 + 9 × 100 + 0 + 5 × 1
(or)
70,00,000 + 6,00,000 + 70,000 + 900 + 5
Q.5In the Indian System of Numeration, the number 67999037 is written as 6,79,99,037v
Q.6The successor of a one-digit number is always a one-digit number 9 + 1 = 10v
Q.7The predecessor of a 3-digit number is always a 3 or 4 digit number 100 – 1 = 99v
Q.888888 = 8 × 10000 + 8 × 100 + 8 × 10 + 8 × 1v
Q.9How many ten thousands are there in the smallest 6 digit number?v
Answer:Smallest 6 digit number = 1,00,000
= \(\frac{100000}{10000}\) = 10
1 Lakh = 10 Ten Thousands
Q.10Using the digits 5, 2, 0, 7, 3 forms the largest 5 digit number and the smallest 5 digit number.v
Answer:Given digits = 5, 2, 0, 7, 3
Largest 5 digit number – 75320
Smallest 5 digit number – 20357
Q.11Observe the commas and write down the place value of 7. (i) 56,74,56,345 (ii) 567,456,345v
Answer:(i) 70,00,000
(ii) 7,000,000
Q.12Write the following numbers in the International System by using commas. 347056 7345671 634567105 1234567890v
Answer:347,056
7,345,671
634,567,105
1,234,567,890
Q.13Write the largest six-digit number and put commas in the Indian and the International Systems.v
Answer:Largest 6 digit number = 9,99,999
Indian System: 9,99,999 (Nine Lakh Ninety-Nine Thousand Nine Hundred Ninety-Nine)
International System: 999,999 (Nine Hundred Ninety-Nine Thousand, Nine Hundred Ninety-Nine)
Q.14Write the number names of the following numerals in the Indian System. (i) 75,32,105 (ii) 9,75,63,453v
Answer:(i) Seventy-five lakh thirty-two thousand one hundred five.
(ii) Nine crore seventy-five lakh sixty-three thousand four hundred fifty-three.
Q.15Write the number of names in words using the International System. 345,678 8,343,710 103,456,789v
Answer:Three hundred forty-five thousand six hundred seventy-eight.
Eight million three hundred forty-three thousand seven hundred ten.
One hundred three million four hundred fifty-six thousand seven hundred eighty-nine.
Q.16Write the number name in numerals. Two crores thirty lakhs fifty-one thousand nine hundred eighty. Sixty-six million three hundred forty-five thousand twenty-seven. Seven hundred eighty-nine million, two hundred thirteen thousand four hundred fifty-six.v
Answer:2,30,51,980
66,345,027
789,213,456
Q.17Tamil Nadu has about twenty-six thousand three hundred forty-five square kilometres of Forest land. Write the number mentioned in the statement in the Indian System.v
Q.18The number of employees in the Indian Railways is about 10 lakh. Write this in the International System of numeration.v
Answer:1,000,000 (One Million)Objective Type Questions
Q.191 billion is equal tov
- A. 100 crore
- B. 100 million
- C. 100 lakh
- D. 10000 lakh
Q.20The successor of 10 million isv
- A. 1000001
- B. 10000001
- C. 9999999
- D. 100001
Q.21The difference between successor and predecessor of 99999 isv
Q.22The expanded form of the number 6,70,905 isv
- A. 6 × 10000 + 7 × 1000 + 9 × 100 + 5 × 1
- B. 6 × 10000 + 7 × 1000 + 0 × 100 + 9 × 100 + 0 × 10 + 5 × 1
- C. 6 × 1000000 + 7 × 10000 + 0 × 1000 + 9 × 100 + 0 × 10 + 5 × 1
- D. 6 × 100000 + 7 × 10000 + 0 × 1000 + 9 × 100 + 0 × 10 + 5 × 1
Answer:(d) 6 × 100000 + 7 × 10000 + 0 × 1000 + 9 × 100 + 0 × 10 + 5 × 1
Q.26The difference between the smallest number of seven digits and the largest number of six digits is 10.v
Answer:False
Hint: 1000000 – 999999 = 1
Q.27The largest 4 digit number formed by the digits 8, 6, 0, 9 using each digit only once is 9086v
Answer:False
Hint: 9999 – 999 = 9000
Q.28The total number of 4 digit number is 9000v
Q.29Of the numbers 1386787215, 137698890, 86720560, which one is the largest? Which one is the smallest?v
Answer:We know that the number with more digits is greater.
The greatest number is 1386787215
The smallest number is 86720560
Q.30Arrange the following numbers in the descending order: 128435, 10835, 21354, 6348, 25840v
Answer:128435 > 25840 > 21354 > 10835 > 6348
Q.31Write any eight-digit number with 6 in ten lakhs place and 9 in ten-thousandth place.v
Q.32Rajan writes a 3-digit number, using the digits 4, 7, and 9. What are the possible numbers he can write?v
Answer:974, 947, 479, 497, 749, 794
Q.33The password to access my ATM card includes the digits 9, 4, 6, and 8. It is the smallest 4 digit even number. Find the password of my ATM card.v
Answer:Given digits are 9, 4, 6, and 8.
The smallest number with these digits is 4689 Given that it is an even number.
It may be 4698.
So password of the ATM card is 4698.
Q.34Postal Index Number consists of six digits. The first three digits are 6, 3, and 1. Make the largest and the smallest Postal Index Number by using the digits 0, 3, and 6 each only once.v
Answer:Largest Postal Index Number = 631603
Smallest Postal Index Number = 631036
Q.35Which list of numbers is in order from the smallest to the largest?v
- A. 1468, 1486, 1484
- B. 2345, 2435, 2235
- C. 134205, 134208, 154203
- D. 383553, 383548, 383642
Answer:(c) 134205, 134208, 154203
Q.36The Arabian Sea has an area of 1491000 square miles. This area lies between which two numbers?v
- A. 1489000 and 1492540
- B. 1489000 and 1490540
- C. 1490000 and 1490100
- D. 1480000 and 1490000
Answer:(a) 1489000 and 1492540
Q.37The chart below shows the number of newspapers sold as per the Indian Readership Survey in 2018. Which could be the missing number in the table? v
Q.38If Arulmozhi saves ₹ 12 per day then she saves ₹ ____ in 30 days.v
Q.39If a person ‘A’ earns ₹ 1800 in 12 days, then he earns ₹ ____ in a day.v
Answer:\(\frac{1800}{12}=150\)
Q.4045 ÷ (7 + 8) – 2 = _____v
Answer:45 ÷ 15 – 2 = 3 – 2 = 1
Q.413 + 9 × 8 = 96v
Answer:False
Hint: 3 + 9 × 8 = 3 + 72 = 75
Q.427 × 20 – 4 = 136v
Answer:True
Hint: 7 × 20 – 4 = 140 – 4 = 136
Q.4340 + (56 – 6) ÷ 2 = 45v
Answer:False
Hint: 40 + 50 ÷ 2 = 40 + 25 = 65
Q.44The number of people who visited the Public Library for the past 5 months was 1200, 2000, 2450, 3060 and 3200 respectively. How many people visited the library in the last 5 months.v
Answer:People visited the library for past 5 months = 1200 + 2000 + 2450 + 3060 + 3200 = 11910
Total people visited = 11910
Q.45Cheran had a bank savings of ₹ 7,50,250. He withdrew ₹ 5,34,500 for educational purposes. Find the balance amount in his account.v
Answer:Bank Savings of Cheran = ₹ 7,50,250
Withdrew Amount = ₹ 5,34,500
Balance Amount = ₹ 2,15,750
Q.46In a cycle factory, 1560 bicycles were manufactured every day. Find the number of bicycles manufactured in 25 days.v
Answer:Bicycles manufactured in one day = 1560
Bicycles manufactured in 25 days = 1560 × 25
= 39,000 bicycles
Q.47₹ 62,500 was equally distributed as a New Year bonus for 25 employees of a company. How much did each receive?v
Answer:Total amount = Rs 62500
Total number of employees = 25
Bonus amount received by each employee = Rs 62500 ÷ 25
= RS \(\frac{62500}{25}\)
= Rs 2500
Q.48Simplify the following numerical expressions: (i) (10 + 17) ÷ 3 (ii) 12 – [3 – {6 – (5 – 1)}] (iii) 100 + 8 ÷ 2 + {(3 × 2) -6 ÷ 2}v
Answer:(i) (10 + 17) ÷ 3
= 27 ÷ 3
= 9(ii) 12 – [3 – {6 – (5 – 1)}]
= 12 – [3 – (6 – 4)]
= 12 – [3 – 2]
= 12 – 1
= 11
(iii) 100 + 8 ÷ 2 + {(3 × 2) – 6 ÷ 2}
= 100 + 8 ÷ 2 + {6 – 3}
= 100 + 8 ÷ 2 + 3
= 100 + 4 + 3
= 107Objective Type Questions
Q.49The value of 24 ÷ {8 – (3 × 2)} is ______v
- A. 0
- B. 12
- C. 3
- D. 4
Answer:(b) 12
24 ÷ {8 – 3 × 2} = 24 ÷ {8 – 6} = 24 ÷ 2 = 12
Q.50Use BIDMAS and put the correct operator in the box. 2 ….. 6 – 12 ÷ (4 + 2) = 10v
- A. +
- B. –
- C. ×
- D. ÷
Answer:(c) ×
2 ….. 6 – 12 ÷ 6 = 10
⇒ 2 ….. 6 – 2 = 10
⇒ 2 × 6 – 2 = 10
Q.51The nearest 100 of 843 is _____v
Answer:800.
The digit in tens place is 4 < 5
Q.52The nearest 1000 of 756 is ______v
Answer:1000.
The digit in hundred places is 7 ≥ 5
Q.53The nearest 10,000 of 85654 is ______v
Answer:90,000.
The digit in a thousand places is 5 ≥ 5
Q.548567 is rounded off as 8600 to the nearest 10.v
Answer:False
Hint: In one’s place the digit is 7 ≥ 5. So 8580
Q.55139 is rounded off as 100 to the nearest 100.v
Answer:True
Hint: In tens place, we have 3 < 5. So 100
Q.561,70,51,972 is rounded off as 1,70,00,000 to the nearest lakh.v
Answer:False
Hint: In ten thousand places the digit is 5 ≥ 5. So 1,71,000,000
Q.57Round off the following to the given nearest place. (i) 4,065; hundred (ii) 44,555; thousand (iii) 86,943; ten thousand (iv) 50,81,739; lakh (v) 33,75,98,482; ten crorev
Answer:(i) 4100
(ii) 45,000
(iii) 90,000
(iv) 51,00,000
(v) 30,00,00,000
Q.58Estimate the sum of 157826 and 32469 rounded off to the nearest ten thousand.v
Answer:= 157826 + 32469
= 190295
When rounded off to nearest ten thousand = 1,90,000
Decimal numbers can be rounded to the nearest hundredth by observing the digit in the thousandths place.
Q.59Estimate by rounding off each number to the nearest hundred. (i) 8074 + 4178 (ii) 1768977 + 130589v
Answer:(i) 8074 + 4178 = 12,252
When rounded off to nearest hundred 12,300
(ii) 1768977 + 130589 = 18,99,566
When rounded off to nearest hundred = 18,99,600
Q.60The population of a city was 43,43,645 in the year 2001 and 46,81,087 in the year 2011. Estimate the increase in population by rounding off to the nearest thousands.v
Answer:Population in 2001 = 43,43,645
Population in 2011 = 46,81,087
Increase in population = 46,81,087 – 43,43,645 = 3,37,442
When rounded off to the nearest thousand = 3,37,000Objective Type Questions
Q.61The number which on rounding off to the nearest thousand gives 11000 isv
- A. 10345
- B. 10855
- C. 11799
- D. 10056
Q.62The estimation to the nearest hundredth of 76812 isv
- A. 77000
- B. 76000
- C. 76800
- D. 76900
Answer:(c) 76800
In tens place the digit is 1 < 5, So 76800
Q.63The number 9785764 is rounded off to the nearest lakh asv
- A. 9800000
- B. 9786000
- C. 9795600
- D. 9795000
Q.64The estimated difference of 167826 and 2765 rounded off to the nearest thousand isv
- A. 180000
- B. 165000
- C. 140000
- D. 155000
Q.65The difference between the smallest natural number and the smallest whole number is ……….v
Q.67When ……… is added to a number, it remains the same.v
Q.68Division by ………. is not defined.v
Q.69Multiplication by ……… leaves a number unchanged.v
Q.700 is the identity for multiplication of whole numbers.v
Q.71The Sum of two whole numbers is always less than their product.v
Q.72Both addition and multiplication are associative for whole numbers.v
Q.73Both addition and multiplication are commutative for whole numbers.v
Q.74Multiplication is distributive over addition for whole numbers.v
Q.75Name the property being illustrated in each of the cases given below. 75 + 34 = 34 + 75 (12 × 4) × 8 = 12 × (4 × 8) 50 + 0 = 50 50 × 1 = 50 50 × 42 = 50 × 40 + 50 × 2v
Answer:Commutativity for addition
Associativity for multiplication
Zero is the additive identity
One is the multiplicative identity
Distributivity of multiplication over addition
Q.76Use the properties of whole numbers and simplify. (i) 50 × 102 (ii) 500 × 689 – 500 × 89 (iii) 4 × 132 × 25 (iv) 196 + 34 + 104v
Answer:(i) 50 × 102
= 50 × (100 + 2)
= (50 × 100) + (50 × 2)
= 5000 + 100 = 5100
(ii) 500 × 689 – 500 × 89
= 500 × (689 – 89)
= 344500 – 44500
= 300000
= 500 × (689 – 89)
= 500 × 600
= 3,00000
(iii) (4 × 132) × 25
= 4 × (132 × 25)
= (4 × 132) × 25
= 528 × 25
= 13200
= 4 × (132 × 25)
= 4 × 3300
= 13200
(iv) (196 + 34) + 104 = 196 + (34 + 104)
(196 + 34) + 104 = 230 + 104 = 334
196 + (34 + 104) = 196 + 138 = 334Objective Type Questions
Q.77(53 + 49) × 0 isv
- A. 102
- B. 0
- C. 1
- D. 53 + 49 × 0
Q.78The product of a non-zero whole number and its successor is alwaysv
- A. an even number
- B. an odd number
- C. zero
- D. none of these
Answer:(a) an even number
Q.79The whole number that does not have a predecessor isv
- A. 10
- B. 0
- C. 1
- D. none of these
Q.80Which of the following expressions is not zero?v
- A. 0 × 0
- B. 0 + 0
- C. \(\frac{2}{0}\)
- D. \(\frac{0}{2}\)
Answer:(c) \(\frac{2}{0}\)
Dividing by 0 is not defined.
Q.81Which of the following is not true?v
- A. (4237 + 5498) + 3439 = 4237 + (5498 + 3439)
- B. (4237 × 5498) × 3439 = 4237 × (5498 × 3439)
- C. 4237 + 5498 × 3439 = (4237 + 5498) × 3439
- D. 4237 × (5498 + 3439) = (4237 × 5498) + (4237 × 3439)
Answer:(c) 4237 + 5498 × 3439 = (4237 + 5498) × 3439
Q.82Try to open my locked suitcase which has the biggest 5 digit odd number as the password comprising the digits 7, 5, 4, 3 and 8. Find the password.v
Q.83Mullaikodi has 25 bags of apples. In each bag, there are 9 apples. She shares them equally amongst her 6 friends. How many apples does each get? Are there any apples left over?v
Answer:No of apple bags = 25
Apples in each bag = 9
Total no of apples = 25 × 9 = 225
Apples shared among her 6 friends = 225 ÷ 6
So, among her 6 friends, each of them gets 37 apples and 3 apples are leftover.
Q.84Poultry has produced 15472 eggs and fits 30 eggs in a tray. How many trays do they need?v
Answer:No of eggs produced = 15472
No of eggs fits in a tray = 30
No of trays required = 15472 ÷ 30
Trays required = 515 + 1 (to fit the remaining 22 eggs) = 516
Quotient = 515
Remainder = 22Challenging Problems
Q.85Anbu asks Arivu Selvi to guess a five-digit odd number. He gives the following hints. The digit in the 1000s place is less than 5 The digit in the 100s place is greater than 6 The digit in the 10s place is 8. What is Arivu Selvi’s answer? Does she give more than one answer?v
Answer:There are more than one answers.
One of them is 54781
Some of the other numbers maybe 64783, 74785, 84787 and so on.
Q.86A Music concert is taking place in a stadium. A total of 7,689 chairs are to be put in rows of 90. (i) How many rows will there be? (ii) Will there be any chairs left over?v
Answer:Total no of chairs to be put = 7,689
Chairs in each row = 90
No of rows = 7689 ÷ 90
Hence, 84 + 1 = 85 rows are required to fill 7650 chairs
Chairs left over = 79 (If the no of rows = 84)
Q.87Round off the seven-digit number 29,75,842 to the nearest lakhs and ten lakhs. Are they the same?v
Answer:Yes. Both are same (30,00,000)
Q.88Find the 5 or 6 or 7 digit numbers from a newspaper or a magazine to get a rounded number to the nearest ten thousand.v
Answer:(i) 14276 \(\simeq\) 10000
(ii) 1,86945 \(\simeq\) 1,90000