1. Use the digits 6, 4, 7, 2, 1, 9, 8, 5, and 0 to write the number in the Indian System and International System. Also, write their number names.

a. The largest possible number
b. The smallest possible number

2. Round off 89,63,72,541 to the nearest:

a. Tens



Answer :

Sure, let's go through the problem step-by-step.

### Question 1: Use the digits 6, 4, 7, 2, 1, 9, 8, 5, and 0 to write the numbers in the Indian and International Systems and also write their number names.

#### (a) The largest possible number

1. Largest possible number:
- Arrange the digits in descending order: 9, 8, 7, 6, 5, 4, 2, 1, 0
- The largest possible number is 987654210.

2. Number names:
- Indian System: Ninety-eight Crore, Seventy-six Lakh, Fifty-four Thousand, Two Hundred and Ten
- International System: Nine Hundred Eighty-seven Million, Six Hundred Fifty-four Thousand, Two Hundred and Ten

3. Indian System:
- 987654210 is written as 98,76,54,210 in the Indian system.
- The number name is "Ninety-eight Crore, Seventy-six Lakh, Fifty-four Thousand, Two Hundred and Ten".

4. International System:
- 987654210 is written as 987,654,210 in the International system.
- The number name is "Nine Hundred Eighty-seven Million, Six Hundred Fifty-four Thousand, Two Hundred and Ten".

#### (b) The smallest possible number

1. Smallest possible number:
- Arrange the digits in ascending order: 0, 1, 2, 4, 5, 6, 7, 8, 9.
- The smallest possible number, ensuring it's valid (non-zero starting,) is 102456789.

2. Number names:
- Indian System: One Crore, Two Lakh, Forty-five Thousand, Six Hundred and Seventy-nine
- International System: One Hundred Two Million, Four Hundred Fifty-six Thousand, Seven Hundred and Eighty-nine

3. Indian System:
- 102456789 is written as 10,24,56,789 in the Indian system.
- The number name is "Ten Crore, Twenty-four Lakh, Fifty-six Thousand, Seven Hundred and Eighty-nine".

4. International System:
- 102456789 is written as 102,456,789 in the International system.
- The number name is "One Hundred Two Million, Four Hundred Fifty-six Thousand, Seven Hundred and Eighty-nine".

### Question 2: Round off 89,63,72,541 to the nearest tens

1. Given number: 89,63,72,541

2. Rounding off to the nearest tens:
- To round 89,63,72,541 to the nearest tens, we look at the units digit (1 in this case).
- Since 1 is less than 5, we round down.

3. Rounded number:
- 89,63,72,541 rounded to the nearest ten is 89,63,72,540.

Thus, the answer to the rounding question is 89,63,72,540.