Unit Test (Solution): Large Numbers Around Us | Mathematics (Ganita Prakash) Class 7 - New NCERT PDF Download

Maximum Marks: 30
Attempt all questions

• Question numbers 1 to 5 carry 1 mark each.
• Question numbers 6 to 8 carry 2 marks each.
• Question numbers 9 to 11 carry 3 marks each.
• Question numbers 12 to 13 carry  5 marks each.

Q1. How many zeros are in one crore? (1 Mark)
(a) 5
(b) 7
(c) 9
(d) 8
Ans: (b) 7

Q2. In the Indian system, the number 5,23,456 is read as: (1 Mark)
(a) Five lakh twenty-three thousand four hundred fifty-six
(b) Five crore twenty-three thousand four hundred fifty-six
(c) Fifty-two lakh three thousand four hundred fifty-six
(d) Five lakh three thousand four hundred fifty-six
Ans: (a) Five lakh twenty-three thousand four hundred fifty-six

Q3. What is the place value of 7 in the number 4,87,231? (1 Mark)
(a) 7,000
(b) 70,000
(c) 7,00,000
(d) 700
Ans: (a) 7,000

Q4. State whether the following statement is True or False:  (1 Mark)
"In the International system, 1 crore is equal to 10 million."
Ans: True

Q5. What is the smallest 7-digit number in the Indian system? (1 Mark)
(a) 1,00,000
(b) 10,00,000
(c) 1,00,00,000
(d) 10,00,00,000
Ans: (b) 10,00,000

Q6. Write the number 8,76,543 in words using the Indian system and the International system. (2 Mark)
Ans: Indian system: Eight lakh seventy-six thousand five hundred forty-three
International system: Eight hundred seventy-six thousand five hundred forty-three

Q7. Round the number 4,56,789 to the nearest ten thousand. (2 Mark)
Ans: The thousands digit is 6. Since 6 ≥ 5, round up the ten thousands digit (5) to 6.
Rounded number: 4,60,000

Q8. Calculate the number of days required to taste 1 lakh varieties of an item if you taste 4 varieties per day. (2 Mark)
Ans: 1 lakh = 1,00,000 varieties
Days required = 1,00,000 ÷ 4 = 25,000 days

Q9. Write the number 3,45,67,890 in expanded form using the Indian system. (3 Mark)
Ans: 3,45,67,890 = (3 × 1,00,00,000) + (4 × 10,00,000) + (5 × 1,00,000) + (6 × 10,000) + (7 × 1,000) + (8 × 100) + (9 × 10) + (0 × 1)

Q10. A building is 5 metres per floor. How many floors are needed to reach a height of 250 metres? If the height is increased to 260 metres, how many floors are required (round up to the nearest whole number)? (3 Mark)
Ans: For 250 metres:
Number of floors = 250 ÷ 5 = 50 floors
For 260 metres:
Number of floors = 260 ÷ 5 = 52 floors
Since the result is a whole number, no rounding is needed.
Answer: 50 floors for 250 metres, 52 floors for 260 metres.

Q11. Compare 25 lakh and 2 million using '<', '>', or '='. Show your working. (3 Mark)
Ans: 25 lakh = 25 × 1,00,000 = 25,00,000
2 million = 2 × 1,000,000 = 20,00,000
Since 25,00,000 > 20,00,000,
25 lakh > 2 million

Q12. A city has a population of 85,00,000. If each bus can carry 40 people, calculate how many buses are needed to transport the entire population. Round the number of buses to the nearest thousand and explain why rounding is useful in this context. (5 Mark)
Ans: Population = 85,00,000
People per bus = 40
Number of buses = 85,00,000 ÷ 40 = 2,12,500 buses
To round to the nearest thousand:
The hundreds digit is 5. Since 5 ≥ 5, round up the thousands digit (2) to 3.
Rounded number of buses = 2,13,000

Q13. Using the shortcut method, calculate 236 × 25. Then, verify the answer using standard multiplication. Calculate 236 × 50 using the shortcut method and verify using standard multiplication. (5 Mark)
Ans: For 236 × 25 (Shortcut Method):
Since 25 = 100 ÷ 4,
236 × 25 = (236 ÷ 4) × 100
236 ÷ 4 = 59
59 × 100 = 5,900
Verification (Standard Multiplication):
236 × 25 = 236 × (20 + 5)
= (236 × 20) + (236 × 5)
= 4,720 + 1,180 = 5,900
For 236 × 50 (Shortcut Method):
Since 50 = 100 ÷ 2,
236 × 50 = (236 ÷ 2) × 100
236 ÷ 2 = 118
118 × 100 = 11,800
Verification (Standard Multiplication):
236 × 50 = 236 × (50)
= 11,800