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.
