How big is a lakh?
Compare it with something you know.
Estu and the rice varieties
Our country once had about 1 lakh varieties of rice. Estu tastes one new variety every day, and he lives for 100 years.
Roxie says: “What if we ate 2 new varieties every day?” Would that reach 1 lakh in 100 years?
What this lesson covers
The idea
We get a better sense of how big a large number or measurement is by comparing it with familiar numbers or quantities and checking how many times bigger it is.
Estu and the rice varieties
Our country once had about 1 lakh varieties of rice. Estu tastes one new variety every day, and he lives for 100 years.
Roxie says: “What if we ate 2 new varieties every day?” Would that reach 1 lakh in 100 years?
- Yes
- No
Taste and compare
Choose how many new varieties to taste every day. The bar adds up one lifetime of 100 years.
Use something familiar
A lifetime of 100 years has 365 × 100 = 36,500 days. One variety a day gives only 36,500, and two a day gives 73,000. Even that is short! Only three a day passes 1 lakh.
To feel how big a large number is, compare it with something familiar and ask how many times bigger it is. 1 lakh days is about 274 years, nearly 3 lifetimes.
- 1 lakh of… | Compare with something familiar
- days | about 274 years of life
- people | standing shoulder to shoulder, a line about 38 km long
- hairs | most heads have 80,000 to 1,20,000 hairs
- seats | the Ahmedabad cricket stadium seats more than 1 lakh
Notes
To get a sense of a large number or measurement, compare it with something familiar and check how many times bigger it is. 100 years is 36,500 days, so 1 lakh days is nearly 3 lifetimes.
Check yourself
How many days are there in 100 years? Count 365 days in a year.
Answer: 36500 days
365 × 100 = 36,500 days.
The Statue of Unity is about 180 m tall. The Kunchikal waterfall drops about 450 m. How many times as big as the statue is the drop?
Answer: 2.5
450 ÷ 180 = 2.5. The drop is 2½ times the height of the statue.
Roxie says 1 lakh is a big number: 1 lakh days is 274 years. Estu says it is small: 1 lakh hairs fit on one head. Who is right?
- Both are right — correct. Yes! How big a number feels depends on what we compare it with.
- Only Roxie. Estu has a point too: next to the hairs on one head, 1 lakh looks small.
- Only Estu. Roxie has a point too: next to a lifetime of days, 1 lakh is huge.