A Lakh Varieties!

Eshwarappa is a farmer in Chintamani, a town in Karnataka. He visits the market regularly to buy seeds for his rice field. During one such visit he overheard a conversation between Ramanna and Lakshmamma. Ramanna said, “Earlier our country had about a lakh varieties of rice. Farmers used to preserve different varieties of seeds and use them to grow rice. Now, we only have a handful of varieties. Also, farmers have to come to the market to buy seeds”. Lakshmamma said, “There is a seed bank near my house. So far, they have collected about a hundred indigenous varieties of rice seeds from different places. You can also buy seeds from there.” You may have heard the word ‘lakh’ before. Do you know how big one lakh is? Let us find out. Eshwarappa shared this incident with his daughter Roxie and son Estu . Estu was surprised to know that there were about one lakh varieties of rice in this country. He wondered “One lakh! So far I have only tasted 3 varieties. If we tried a new variety each day, would we even come close to tasting all the varieties in a lifetime of 100 years?” What do you think? Guess.

But how much is one lakh? Observe the pattern and fill in the boxes given below.

Roxie and Estu found that if they ate one variety of rice a day, they would come nowhere close to a lakh in a lifetime! Roxie suggests, “What if we ate 2 varieties of rice every day? Would we then be able to eat 1 lakh varieties of rice in 100 years?”

What if a person ate 3 varieties of rice every day? Will they be able to taste all the lakh varieties in a 100 year lifetime? Find out.

Estu said, “We know how many days there are in a year—365, if we ignore leap years. If we live for y years, the number of days in our lifetime will be 365 × y.”

Choose a number for y. How close to one lakh is the number of days in y years, for the y of your choice?

Figure it Out

1. According to the 2011 Census, the population of the town of Chintamani was about 75,000. How much less than one lakh is 75,000?

2. The estimated population of Chintamani in the year 2024 is 1,06,000. How much more than one lakh is 1,06,000?

3. By how much did the population of Chintamani increase from 2011 to 2024?

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.

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?

__{.m-red}Which is taller — The Statue of Unity or this building? How much taller? __________m.

We can see that the height of the Statue of Unity is close to 4 times the height of Somu’s building.

How much taller is the Kunchikal waterfall than Somu's building? ____________m.

How many floors should Somu’s building have to be as high as the waterfall? ____________ .

Is One Lakh a Very Large Number?

Eshwarappa asked Roxie and Estu, “Is a lakh big or small?” Roxie feels that 1 lakh is a large number: • “We had one lakh varieties of rice — that is a lot.” • “Living 1 lakh days would mean living for 274 years — that is a really long time!” • “If 1 lakh people stood shoulder to shoulder in a line they could stretch as far as 38 kilometres.” Estu, however, thinks it is not that big: • “Do you know that the cricket stadium in Ahmedabad has a seating capacity of more than 1 lakh? One lakh people in such a small area!” • “Most humans have 80,000 to 1,20,000 hairs on their heads. Imagine, 1 lakh hairs fit in such a tiny space!” • “I heard that there are some species of fish where a female fish can lay almost one lakh eggs at once very comfortably. Some even lay tens of lakhs of eggs at a time.”

How do you view a lakh — is a lakh big or small?

Reading and Writing Numbers

We have already been using commas for 5-digit numbers like 45,830 in the Indian place value system. As numbers grow bigger, using commas helps in reading the numbers easily. We use a comma in between the digits representing the “ten thousands” place and the “one lakh” place as you have seen just before (1,00,000). The number name of 12,78,830 is twelve lakh seventy eight thousand eight hundred thirty. Similarly, the number 15,75,000 in words is fifteen lakh seventy five thousand.

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

Write the corresponding number in the Indian place value system for each of the following: (a) One lakh twenty three thousand four hundred and fifty six (b) Four lakh seven thousand seven hundred and four (c) Fifty lakhs five thousand and fifty (d) Ten lakhs two hundred and thirty five