Page 3 Solutions
Fill in the Blanks (Lakh Introduction)
3,00,000 is read as:
Answer: Three lakh
4,00,000 is read as:
Answer: Four lakh
5,00,000 is read as:
Answer: Five lakh
6,00,000 is read as:
Answer: Six lakh
7,00,000 is read as:
Answer: Seven lakh
8,00,000 is read as:
Answer: Eight lakh
9,00,000 is read as:
Answer: Nine lakh
4,50,000 read as:
Answer: Four lakh fifty thousand
7,49,192 is read as:
Answer: Seven lakh forty nine thousand one hundred and ninety two
Do these (Page 3)
1) Read the numbers 3,51,645 and 9,38,715.
Answer:
• 3,51,645: Three lakh fifty one thousand six hundred and forty five.
• 9,38,715: Nine lakh thirty eight thousand seven hundred and fifteen.
• 3,51,645: Three lakh fifty one thousand six hundred and forty five.
• 9,38,715: Nine lakh thirty eight thousand seven hundred and fifteen.
2) Write any five 6-digit numbers using the digits 7, 4, 9 and 3. Express them in word form.
Answer: (Repeating digits to make 6-digit numbers)
i) 7,74,933: Seven lakh seventy four thousand nine hundred and thirty three.
ii) 4,93,749: Four lakh ninety three thousand seven hundred and forty nine.
iii) 9,74,374: Nine lakh seventy four thousand three hundred and seventy four.
iv) 3,47,937: Three lakh forty seven thousand nine hundred and thirty seven.
v) 7,49,374: Seven lakh forty nine thousand three hundred and seventy four.
i) 7,74,933: Seven lakh seventy four thousand nine hundred and thirty three.
ii) 4,93,749: Four lakh ninety three thousand seven hundred and forty nine.
iii) 9,74,374: Nine lakh seventy four thousand three hundred and seventy four.
iv) 3,47,937: Three lakh forty seven thousand nine hundred and thirty seven.
v) 7,49,374: Seven lakh forty nine thousand three hundred and seventy four.
Page 4 Solutions
Read the following (Ten lakh)
20,00,000 read as:
Answer: Twenty lakh
30,00,000 read as:
Answer: Thirty lakh
40,00,000 read as:
Answer: Forty lakh
50,00,000 read as:
Answer: Fifty lakh
60,00,000 read as:
Answer: Sixty lakh
70,00,000 read as:
Answer: Seventy lakh
Do these (Page 4)
1) Read the numbers 65,14,852 and 29,36,429.
Answer:
• 65,14,852: Sixty five lakh fourteen thousand eight hundred and fifty two.
• 29,36,429: Twenty nine lakh thirty six thousand four hundred and twenty nine.
• 65,14,852: Sixty five lakh fourteen thousand eight hundred and fifty two.
• 29,36,429: Twenty nine lakh thirty six thousand four hundred and twenty nine.
2) Write any five 7-digit numbers using the digits 2, 8, 5 and 1. Express them in word form.
Answer:
i) 28,51,285: Twenty eight lakh fifty one thousand two hundred and eighty five.
ii) 85,21,852: Eighty five lakh twenty one thousand eight hundred and fifty two.
iii) 51,82,518: Fifty one lakh eighty two thousand five hundred and eighteen.
iv) 12,85,128: Twelve lakh eighty five thousand one hundred and twenty eight.
v) 25,81,258: Twenty five lakh eighty one thousand two hundred and fifty eight.
i) 28,51,285: Twenty eight lakh fifty one thousand two hundred and eighty five.
ii) 85,21,852: Eighty five lakh twenty one thousand eight hundred and fifty two.
iii) 51,82,518: Fifty one lakh eighty two thousand five hundred and eighteen.
iv) 12,85,128: Twelve lakh eighty five thousand one hundred and twenty eight.
v) 25,81,258: Twenty five lakh eighty one thousand two hundred and fifty eight.
Page 6 Solutions - EXERCISE 1
1) Identify the biggest number among the following:
A) 7,26,581 B) 7,36,581 C) 7,16,584 D) 7,96,581
Answer: D) 7,96,581
2) What is the place value of 8 in 7,08,643?
A) 80,000 B) 800 C) 8,000 D) 0
Answer: C) 8,000
3) Write the following numbers in words:
a) 1,25,602: One lakh twenty five thousand six hundred and two.
b) 5,58,946: Five lakh fifty eight thousand nine hundred and forty six.
c) 9,57,524: Nine lakh fifty seven thousand five hundred and twenty four.
b) 5,58,946: Five lakh fifty eight thousand nine hundred and forty six.
c) 9,57,524: Nine lakh fifty seven thousand five hundred and twenty four.
4) Write the following in numbers:
a) Fourteen lakh thirty five thousand and fifteen = 14,35,015
b) Seventy four lakh sixty two thousand four hundred and sixty five = 74,62,465
b) Seventy four lakh sixty two thousand four hundred and sixty five = 74,62,465
5) Read the following and answer:
Vemanna bought a house for ₹45,87,000 and a plot beside it, at ₹18,56,000. He paid a total amount of ₹64,43,000.
• The cost of the house (in words): Forty five lakh eighty seven thousand rupees.
• The cost of the plot (in words): Eighteen lakh fifty six thousand rupees.
• The total cost of the house and the plot is (in words): Sixty four lakh forty three thousand rupees.
• The cost of the plot (in words): Eighteen lakh fifty six thousand rupees.
• The total cost of the house and the plot is (in words): Sixty four lakh forty three thousand rupees.
Page 8 Solutions
Ten Crore Section - Fill in the blanks
The greatest 8-digit number is _________
Answer: 9,99,99,999
What happens when 1 is added to this?
Answer: We get 10,00,00,000 (Ten Crore), which is the smallest 9-digit number.
What is the biggest 9-digit number?
Answer: 99,99,99,999 (Ninety nine crore ninety nine lakh ninety nine thousand nine hundred and ninety nine)
Page 12 Solutions
Do these (Page 12)
1) Write the following numerals in standard form and also write them in words:
a) 721594
• Standard form: 7,21,594
• In words: Seven lakh twenty one thousand five hundred and ninety four.
b) 4632584
• Standard form: 46,32,584
• In words: Forty six lakh thirty two thousand five hundred and eighty four.
• Standard form: 7,21,594
• In words: Seven lakh twenty one thousand five hundred and ninety four.
b) 4632584
• Standard form: 46,32,584
• In words: Forty six lakh thirty two thousand five hundred and eighty four.
2) Express the following numbers in expanded form:
a) 40,63,52,456
= 40,00,00,000 + 0 + 60,00,000 + 3,00,000 + 50,000 + 2,000 + 400 + 50 + 6
b) 73,45,46,800
= 70,00,00,000 + 3,00,00,000 + 40,00,000 + 5,00,000 + 40,000 + 6,000 + 800 + 0 + 0
= 40,00,00,000 + 0 + 60,00,000 + 3,00,000 + 50,000 + 2,000 + 400 + 50 + 6
b) 73,45,46,800
= 70,00,00,000 + 3,00,00,000 + 40,00,000 + 5,00,000 + 40,000 + 6,000 + 800 + 0 + 0
Page 14 Solutions
Activity 1 (b)
Write the standard form, expanded form and the number in words for the number represented based on the beads on the spike abacus:
Beads on spikes: TC=5, Cr=6, TL=1, L=4, TTh=2, Th=6, H=3, T=2, O=5
• Number in standard form: 56,14,26,325
• Expanded form: 50,00,00,000 + 6,00,00,000 + 10,00,000 + 4,00,000 + 20,000 + 6,000 + 300 + 20 + 5
• Number in words: Fifty six crore fourteen lakh twenty six thousand three hundred and twenty five.
• Expanded form: 50,00,00,000 + 6,00,00,000 + 10,00,000 + 4,00,000 + 20,000 + 6,000 + 300 + 20 + 5
• Number in words: Fifty six crore fourteen lakh twenty six thousand three hundred and twenty five.
Do these (Page 14)
1) Draw the spike abacus for the following numbers:
(Representation details for drawing):
1) 54,56,705: Spikes from TL to O -> TL:5, L:4, TTh:5, Th:6, H:7, T:0, O:5
2) 6,27,12,545: Spikes from Cr to O -> Cr:6, TL:2, L:7, TTh:1, Th:2, H:5, T:4, O:5
3) 72,61,50,305: Spikes from TC to O -> TC:7, Cr:2, TL:6, L:1, TTh:5, Th:0, H:3, T:0, O:5
1) 54,56,705: Spikes from TL to O -> TL:5, L:4, TTh:5, Th:6, H:7, T:0, O:5
2) 6,27,12,545: Spikes from Cr to O -> Cr:6, TL:2, L:7, TTh:1, Th:2, H:5, T:4, O:5
3) 72,61,50,305: Spikes from TC to O -> TC:7, Cr:2, TL:6, L:1, TTh:5, Th:0, H:3, T:0, O:5
2) Write the numerals in standard form for the following number names:
a) Twenty five lakh five thousand eight hundred and forty one = 25,05,841
b) Five crore twenty lakh six thousand two hundred and five = 5,20,06,205
b) Five crore twenty lakh six thousand two hundred and five = 5,20,06,205
3) Write the numerals in standard form for the following expanded forms:
a) 60,00,000 + 0 + 50,000 + 1,000 + 0 + 8 = 60,51,008
b) 20,00,00,000 + 80,00,000 + 40,000 + 500 + 1 = 20,80,40,501
b) 20,00,00,000 + 80,00,000 + 40,000 + 500 + 1 = 20,80,40,501
Page 16 Solutions - EXERCISE 2
1) On the basis of given abacuses, state which of the following option is true:
Abacus (i): TL:1, L:3, TTh:1, Th:1, H:4, T:2, O:4 → 13,11,424
Abacus (ii): TL:1, L:3, TTh:2, Th:3, H:2, T:2, O:5 → 13,23,225
Answer: B) i < ii
2) Write the following numerals in standard form:
a) 24536192 = 2,45,36,192
b) 900000100 = 90,00,00,100
b) 900000100 = 90,00,00,100
3) Write the following numerals in words:
a) 93,53,26,491: Ninety three crore fifty three lakh twenty six thousand four hundred and ninety one.
b) 70,30,10,400: Seventy crore thirty lakh ten thousand four hundred.
b) 70,30,10,400: Seventy crore thirty lakh ten thousand four hundred.
4) Write expanded form for the following numerals:
a) 3,49,85,294: 3,00,00,000 + 40,00,000 + 9,00,000 + 80,000 + 5,000 + 200 + 90 + 4
b) 50,23,80,050: 50,00,00,000 + 20,00,000 + 3,00,000 + 80,000 + 50
b) 50,23,80,050: 50,00,00,000 + 20,00,000 + 3,00,000 + 80,000 + 50
5) Write the number in standard form for the following:
a) Forty five lakh thirty three thousand six hundred and eighty four = 45,33,684
b) 5 crore + 20 lakh + 9 lakh + 40 thousand + 2 thousand + one hundred + 2 ten + 8 one = 5,29,42,128
b) 5 crore + 20 lakh + 9 lakh + 40 thousand + 2 thousand + one hundred + 2 ten + 8 one = 5,29,42,128
6) Distance between Sun and Earth is 14,95,97,870 km. Write in standard & expanded form:
• Standard Form: 14,95,97,870
• Expanded Form: 10,00,00,000 + 4,00,00,000 + 90,00,000 + 5,00,000 + 90,000 + 7,000 + 800 + 70 + 0
• Expanded Form: 10,00,00,000 + 4,00,00,000 + 90,00,000 + 5,00,000 + 90,000 + 7,000 + 800 + 70 + 0
Page 18 Solutions
Sankhyavadhanam Circle Box Solution
The number is:
Answer: 37,52,33,749
Do these (Page 18)
Write place, place value and face value of the underlined digit:
a) 43, 84,304
• Place: Lakhs | Place value: 3,00,000 | Face value: 3
b) 73, 67,245
• Place: Thousands | Place value: 7,000 | Face value: 7
c) 68,98,23,052
• Place: Hundreds | Place value: 0 | Face value: 0
d) 97, 63, 05, 100
• Place: Ten Lakhs | Place value: 60,00,000 | Face value: 6
Page 20 Solutions - EXERCISE 3
1) The biggest 5-digit number formed with digits 2, 0, 6, 4 and 9 is:
Answer: B) 96,420
2) What is the standard form of "fifty nine crore seventy lakh fifty eight thousand nine hundred and ten"?
Answer: A) 59,70,58,910
3) Write place, place-value and face-value for the underlined digits:
a) 73,58,942 → Place: Lakhs | Place-value: 3,00,000 | Face-value: 3
b) 40,73,35,536 → Place: Hundreds | Place-value: 500 | Face-value: 5
c) 82,45,63,125 → Place: Tens | Place-value: 20 | Face-value: 2
d) 64,63,98,524 → Place: Ten Crores | Place-value: 60,00,00,000 | Face-value: 6
b) 40,73,35,536 → Place: Hundreds | Place-value: 500 | Face-value: 5
c) 82,45,63,125 → Place: Tens | Place-value: 20 | Face-value: 2
d) 64,63,98,524 → Place: Ten Crores | Place-value: 60,00,00,000 | Face-value: 6
4) Which digit should be filled in the blank in (47,_5,63,251) for which place-value is 90,00,000?
Answer: 9 (Position is Ten Lakhs place, making the number 47,95,63,251).
5) Compare the following numbers using (>, < or =):
1) 87,83,93,790 > 8,29,80,758
2) 9,00,20,403 < 40,09,53,400
2) 9,00,20,403 < 40,09,53,400
6) Arrange in ascending order:
64,34,68,735; 10,29,47,026; 1,93,85,702; 14,89,27,131; 10,91,25,456
Answer:
1,93,85,702 < 10,29,47,026 < 10,91,25,456 < 14,89,27,131 < 64,34,68,735
1,93,85,702 < 10,29,47,026 < 10,91,25,456 < 14,89,27,131 < 64,34,68,735
7) Arrange in descending order:
74,89,32,165; 48,29,30,456; 6,95,39,821; 98,43,26,834; 28,93,54,124
Answer:
98,43,26,834 > 74,89,32,165 > 48,29,30,456 > 28,93,54,124 > 6,95,39,821
98,43,26,834 > 74,89,32,165 > 48,29,30,456 > 28,93,54,124 > 6,95,39,821
Page 24 Solutions
Do these (Page 24)
1) Write the following numerals in standard forms in International system and write the number names:
a) 4753625
• Standard form: 4,753,625
• Name: Four million seven hundred fifty three thousand six hundred twenty five.
b) 700400300
• Standard form: 700,400,300
• Name: Seven hundred million four hundred thousand three hundred.
• Standard form: 4,753,625
• Name: Four million seven hundred fifty three thousand six hundred twenty five.
b) 700400300
• Standard form: 700,400,300
• Name: Seven hundred million four hundred thousand three hundred.
2) Write the following numerals in the International system:
a) Three hundred thousands = 300,000
b) 5 millions = 5,000,000
b) 5 millions = 5,000,000
Page 26 Solutions
Think and say
One million = ________ lakhs.
Answer: 10 lakhs
Page 28 Solutions - EXERCISE 4
1) Write the following numerals in standard form by putting commas, according to International system:
a) 4528973 = 4,528,973
b) 901247381 = 901,247,381
c) 200200200 = 200,200,200
b) 901247381 = 901,247,381
c) 200200200 = 200,200,200
2) Write the number names for the following numbers in International system:
a) 1,200,000: One million two hundred thousand.
b) 7,521,256: Seven million five hundred twenty one thousand two hundred fifty six.
b) 7,521,256: Seven million five hundred twenty one thousand two hundred fifty six.
3) Answer the following questions:
a) 1 lakh = 100 thousands.
b) 1 million = 10 lakhs.
c) 1 crore = 10 millions.
d) 1 hundred million = 10 crores.
e) 1 million = 1000 thousands.
b) 1 million = 10 lakhs.
c) 1 crore = 10 millions.
d) 1 hundred million = 10 crores.
e) 1 million = 1000 thousands.
4) Identify the place of the digit 7 in the number 672,443,810:
Answer: B) ten millions
5) One million = ________ thousands:
Answer: C) 1000
Page 32 Solutions
Do these (Page 32)
1. Write the Hindu - Arabic numbers for the Roman numerals given:
a) LXXXIX = 50 + 10 + 10 + 10 + (10 - 1) = 89
b) LXV = 50 + 10 + 5 = 65
b) LXV = 50 + 10 + 5 = 65
2. Write the Roman numerals for the Hindu - Arabic numbers:
a) 39 = 30 + 9 = XXXIX
b) 92 = 90 + 2 = XCII
b) 92 = 90 + 2 = XCII
Page 34 Solutions - EXERCISE 5
1. The Roman numeral for 63 is:
Answer: A) LXIII
2. What number does the Roman numeral LIV represent?
Answer: B) 54
3. Convert these Hindu - Arabic numbers into Roman numerals:
a) 7 = VII
b) 78 = LXXVIII
c) 56 = LVI
b) 78 = LXXVIII
c) 56 = LVI
4. Convert these Roman numerals into Hindu - Arabic Numbers:
a) XII = 12
b) LX = 60
c) C = 100
b) LX = 60
c) C = 100
5. Use <, > or = to compare:
a) LIII (53) > XLIII (43)
b) LXX (70) < LXXX (80)
b) LXX (70) < LXXX (80)
6. Circle the numeral that is miswritten in each row:
a) XLV, XXXXX, XIX (Reason: X cannot be repeated more than 3 times)
b) VV, XIII, XC (Reason: V is never repeated)
c) LXXXIII, LXXXIII, LXXXIII (Note: All three are valid, if one had extra X it would be invalid)
b) VV, XIII, XC (Reason: V is never repeated)
c) LXXXIII, LXXXIII, LXXXIII (Note: All three are valid, if one had extra X it would be invalid)
7. Apart from clocks and watches, write the places where we see Roman numerals:
Answer: Class/Grade numbers in schools, Chapter numbers in textbooks, outline lists/indexes, page numbers in book introductions/prefaces, and monuments/building foundation stones.
Page 36 Solutions - IMPROVE YOUR LEARNING
1. 40000 + ______ + 7043 = 7047043. What should come in the blank?
7,047,043 - 40,000 - 7,043 = 7,000,000
Answer: 70,00,000 (70 Lakhs) or 7,000,000.
Answer: 70,00,000 (70 Lakhs) or 7,000,000.
2. Which of these is the SMALLEST number?
a) 110 ones = 110
b) 40 tens = 400
c) 2 hundreds = 200
d) 1 thousand = 1000
Answer: a) 110 ones
3. Which of the following is NOT a correct expanded form of 3631?
Answer: a) 3+6+3+1
4. David holds up a card which reads 5067. Write 'T' for true, and 'F' for false:
a) This number is an even number. → F (It ends in 7, so it is odd)
b) The place value of the digit in the thousands place is 100. → F (Place value is 5000)
c) Its nearest hundred is 5100. → T (5067 rounds up to 5100)
d) Its predecessor is 5066. → T (5067 - 1 = 5066)
b) The place value of the digit in the thousands place is 100. → F (Place value is 5000)
c) Its nearest hundred is 5100. → T (5067 rounds up to 5100)
d) Its predecessor is 5066. → T (5067 - 1 = 5066)
5. A printing machine printed a total of 1 million worksheets. Write the number equal to 1 million in the Hindu-Arabic system:
Answer: 10,00,000 (Ten Lakhs)
6. Rohan wrote Seventy Lakhs as 7,000,000 and read it as Seven Million. Write whether Rohan's answer is correct or not and provide one reason:
Answer: Correct.
Reason: Seventy Lakhs in the Hindu-Arabic system equals 70,00,000. In the International System, grouping digits by threes gives 7,000,000, which is equal to 7 Million.
Reason: Seventy Lakhs in the Hindu-Arabic system equals 70,00,000. In the International System, grouping digits by threes gives 7,000,000, which is equal to 7 Million.
7. In a book the preface ends on page "xiv". Write the page number in Hindu-Arabic numbers:
Answer: 14
8. Meena and Zareena are making numbers with cards: 4, 6, 0, 8, 1, 3
a) Greatest and Smallest 6-digit numbers:
• Greatest 6-digit number = 8,64,310
• Smallest 6-digit number = 1,03,468 (Note: 0 cannot be the leading digit)
b) Place value of 3 in the smallest number (1,03,468):
• Place value of 3 = 3 × 1000 = 3,000 (Three thousand)
c) Reversing digits of smallest number:
• Reversing 1,03,468 gives = 8,64,301
• Original greatest number = 8,64,310
• Comparison: 8,64,301 < 8,64,310
• Result: The new number is less than the original greatest number.
• Greatest 6-digit number = 8,64,310
• Smallest 6-digit number = 1,03,468 (Note: 0 cannot be the leading digit)
b) Place value of 3 in the smallest number (1,03,468):
• Place value of 3 = 3 × 1000 = 3,000 (Three thousand)
c) Reversing digits of smallest number:
• Reversing 1,03,468 gives = 8,64,301
• Original greatest number = 8,64,310
• Comparison: 8,64,301 < 8,64,310
• Result: The new number is less than the original greatest number.
