Class 7 Maths Chapter 1 Worksheet Solutions - Large Numbers Around Us

Section A: Multiple Choice Questions

Q1: Compare and write '<', '>' or '=': 40 thousand _____ 5 lakhs.
a) <
b) >
c) =
d) Cannot be determined

Ans: a) <
Sol: 40 thousand = 40,000; 5 lakhs = 500,000. Since 40,000 < 500,000, the correct option is '<'.

Q2: In the Indian system, how are commas placed for the number 12345678?
a) 1,23,45,678
b) 12,34,56,78
c) 123,456,78
d) 1,234,56,78

Ans: a) 1,23,45,678
Sol: In the Indian system, commas are placed in a 3-2-2-2 pattern from right to left: 1,23,45,678.

Q3 : How many zeros does a hundred lakh have?
a) 5
b) 6
c) 7
d) 8

Ans: c) 7
Sol: Hundred lakh = 100 × 1,00,000 = 1,00,00,000, which has 7 zeros.

Q4: Will the sum of 5,72,345 and 3,19,876 be greater than 8,90,000 or less than 8,90,000?
a) Greater than 8,90,000
b) Less than 8,90,000
c) Equal to 8,90,000
d) Cannot be determined

Ans: a) Greater than 8,90,000
Sol: 5,72,345 + 3,19,876 = 8,92,221. 
Since 8,92,221 > 8,90,000, the sum is greater than 8,90,000. 

Q5 : What is the product of 111 × 111?
a) 12321
b) 12221
c) 12331
d) 12121

Ans: a) 12321

Sol: 111 × 111 = 12321
pattern: 11 × 11 = 121, 
111 × 111 = 12321, 
1111 × 1111 = 1234321.

Section B: Fill in the Blanks

Q6 : Exact value of 3,82,456 + 2,97,543 = ________.

Ans: 6,79,999

Q7 : Write the number 4,50,700 in words: ________.

Ans: Four lakh fifty thousand seven hundred

Q8 : The game of Thoughtful Thousands only has a +1000 button. It should be pressed ________ times to show 70,000.

Ans: 70
Sol: To show 70,000 using a +1000 button, 
press it 70,000 ÷ 1000 = 70 times.

Q9 : According to a census, the population of a town was 82,345 in 2011. Approximately, it was (Round to the nearest ten thousand for approximation) ________.

Ans: 80,000
Sol: 82,345 ≈ 80,000 (round to the nearest ten thousand for approximation).

Section C: Word Problems

Q10: If Priya ate 4 varieties of fruits every day, will she be able to taste all 1 lakh varieties in a 100-year lifetime? Find out.

Ans: Yes, Priya will be able to taste all 1 lakh varieties in a 100-year lifetime.

Sol: 1 lakh = 1,00,000 varieties. 
Priya eats 4 varieties per day. 
In 100 years, days = 100 × 365 = 36,500 (ignoring leap years). 
Varieties tasted = 36,500 × 4 = 1,46,000. Since 1,46,000 > 1,00,000,
Priya can taste all 1 lakh varieties and more.

Q11: Find out how many coins should be stacked to match the height of a monument 150 meters tall. Assume each coin is 2 mm thick.

Ans: 75,000 coins are needed.

Sol: Monument height = 150 meters = 150,000 mm. 
Coin thickness = 2 mm. 
Number of coins = 150,000 ÷ 2 = 75,000.

Q12: A waterfall is 400 meters tall. A building is 4 times the height of a person who is 2 meters tall. How much taller is the waterfall than the building? 

Ans: The waterfall is 392 meters taller than the building.
Sol: Person’s height = 2 meters. Building height = 4 × 2 = 8 meters. Waterfall height = 400 meters. Difference = 400 − 8 = 392 meters.

Q13 : If Sanjay could travel 200 kilometers every day, could he reach a planet 5,00,000 km away in 8 years?

Ans: Yes, Sanjay can reach the planet in 8 years.

Sol: Sanjay travels 200 km/day. 
 In 1 year = 365 days, 
distance = 200 × 365 = 73,000 km. 
In 8 years = 8 × 73,000 = 5,84,000 km. Since 5,84,000 km is greater than 5,00,000 km, Sanjay can reach the planet.

Q14 : A calculator has buttons: +1, +10, +100, +1000, +10000, +100000. One way to get 6083 uses 25 button clicks. Is there another way to get 6083 using fewer button clicks? Write the expression for the same.

Ans: Expression: (6 × 1000) + (8 × 10) + (3 × 1), using 17 clicks.
Sol: To get 6083 with minimal clicks: 6 × 1000 + 8 × 10 + 3 × 1 = 6000 + 80 + 3 = 6083. Clicks = 6 + 8 + 3 = 17. 
The given method uses 25 clicks, and 17 < 25, so this is fewer.

Section D: Think and Answer

Q15: Write any 8-digit number, show its Indian and International place values, and write it in words in both systems.

Ans: Let’s take the number: 84237612

• Indian Place Values: 8,42,37,612
  → 8 crore 42 lakh 37 thousand 612
  In words (Indian): Eight crore forty-two lakh thirty-seven thousand six hundred twelve

• International Place Values: 84,237,612
  → 84 million 237 thousand 612
  In words (International): Eighty-four million two hundred thirty-seven thousand six hundred twelve