Large Numbers Around Us — Question 3

The population increase from 2011 to 2024 = 1,06,000 – 75,000 = 31,000 Getting a Feel of Large Numbers You may have come across interesting facts like these: • The world’s tallest statue is the ‘Statue of Unity’ in Gujarat depicting Sardar Vallabhbhai Patel. Its height is about 180 metres. • Kunchikal waterfall in Karnataka is said to drop from a height of about 450 metres. It is not always easy to get a sense of how big these measurements are. But, we can get a better sense of their size when we compare them with something familiar. Let us see an example. NCERT In-Text Questions (Page 3) Look at the picture on the right. Somu is 1 metre tall. If each floor is about four times his height, what is the approximate height of the building? Solution: Somu’s height = 1 m Height of a floor = 4 × Somu’s height = 4 × 1 m = 4 m Approximate height of the building = Height of 11 floors = 11 × 4 m = 44 m Which is taller — The Statue of Unity or this building? How much taller? __________ m Solution: The Statue of Unity is 180 m tall, and the building is 44 m tall. Difference in heights = 180 – 44 = 136 m. The Statue of Unity is taller than the building. How much taller is the Kunchikal waterfall than Somu’s building? __________ m Solution: Kunchikal waterfall is 450 m tall, and the building is 40 m tall. Difference in heights = 450 – 44 = 406 m Thus, the Kunchikal waterfall is 406 m taller than the building. How many floors should Somu’s building have to be as high as the waterfall? __________ Solution: Each floor is 4 m tall. To match the height of the waterfall (450 m), floors needed = 450 ÷ 4 = 112.5. Thus, building would need approximately 113 floors to be as high as the waterfall. Is One Lakh a Very Large Number? NCERT In-Text Questions (Page 4) How do you view a lakh — is a lakh big or small? Solution: One lakh is a big number in terms of counting numbers. Reading and Writing Numbers NCERT In-Text Questions (Pages 4-5) Write each of the numbers given below in words: (a) 3,00,600 (b) 5,04,085 (c) 27,30,000 (d) 70,53,138 Solution: (a) 3,00,600 → Three lakh six hundred (b) 5,04,085 → Five lakh four thousand eighty-five (c) 27,30,000 → Twenty-seven lakh thirty thousand (d) 70,53,138 → Seventy lakh fifty-three thousand one hundred thirty-eight Write the corresponding number in the Indian place value system for each of the following: (a) One lakh twenty-three thousand four hundred fifty-six (b) Four lakh seven thousand seven hundred four (c) Fifty lakh five thousand fifty (d) Ten lakh two hundred thirty-five Solution: (a) 1,23,456 (b) 4,07,704 (c) 50,05,050 (d) 10,00,235 1.2 Land of Tens NCERT In-Text Questions (Pages 5-6)