MATHS

The number 1,30,285, when written fully in words, one lakh thirty thousand two hundred eighty-five, has 41 letters. Give a 6-digit number name that has the most letters.

7,77,777

In words: Seven lakh seventy-seven thousand seven hundred seventy-seven

Let’s count the letters:

Seven: 5 letters

Lakh: 4 letters

Seventy-seven: 7 + 5 = 12 letters

Thousand: 8 letters

Seven hundred: 5 + 7 = 12 letters

Seventy-seven: 12 letters

How many thousands make a crore?

Ten thousand make a crore.

Write the numbers given below in both the Indian as well as the International systems:

(a) 4735108

(b) 924860

In the Indian system:

(a) 47,35,108: Forty-seven lakh thirty-five thousand one hundred eight,

(b) 9,24,860: Nine lakh twenty-four thousand eight hundred sixty

In the International system:

(a) 4,735,108: Four million seven hundred thirty-five thousand one hundred eight.

(b) 924,860: Nine hundred twenty-four thousand eight hundred sixty.

Complete the following number pattern:

(a) 7 × 2 = ________

77 × 2 = ________

777 × 2 = ________

7777 × 2 = ________

77777 × 2 = ________

777777 × 2 = ________

7 × 2 = 14

77 × 2 = 154

777 × 2 = 1554

7777 × 2 = 15554

77777 × 2 = 155554

777777 × 2 = 1555554

Make necessary reasonable assumptions and answer the following questions:

a) If a computer processes 1,000 files per minute, can it process 1 crore files in a day?

(b) If a person drinks 3 litres of water daily, can they drink 1000 litres in a year?

(c) If a tap fills 600 litres of water every hour, can it fill a 100,000-litre tank in a day?

(a) Total files processed in a day = 1000 × 60 × 24 = 14,40,0.

No, it cannot process 1 crore files in a day.

(b) Water consumed in a year = 3 × 365 = 1095 litres. Yes, it’s possible that a person can drink 1,000 litres in a year.

(c) In a day (24 hours), the tap fills 600 × 24 = 14400 litres. It cannot fill the entire tank in a day.

A calculator has only ‘+1,000’, ‘+100’, and ‘+10’buttons. Write an expression describing the number of button clicks to be made for the following numbers:

(a) 850

(b) 2,140

(c) 10,500

(d) 7,53,020

(a) 850: Expression: 8 × 100 + 5 × 10 = 13 clicks

(b) 2,140: Expression: 2 × 1,000 +1 × 100+ 4 × 10 = 7 clicks

(c) 10,500: Expression: 10 × 1,000 + 5 × 100= 15 clicks

(d) 7,53,020: Expression: 753 × 1,000 + 2 × 10 = 755 clicks