Question

1) How many thousands make a crore?
2) Find the difference between the number 738 and that obtained on reversing its digits.
3) What comes just after 9547999?

Answer 1

Hint:
For the first part of the question, we divide the two values. For the second part, we just reverse the number and subtract it from the original number. And finally, for calculating the last part, we just have to add 1 to the given number (as it has been asked what comes just after the number), but see if a carry-over occurs, and if does, then follow the principle of carry-over.

Complete step by step solution:
1) For solving this question, we just divide one crore (1,00,00,000) by one thousand (1,000).
Number of thousands in a crore = \[\dfrac{{1{\rm{,}}00{\rm{,}}00{\rm{,}}000}}{{1{\rm{,}}000}} = 10,000\]
Hence, there are \[10,000\] thousands in a crore.
2) Given number = \[738\]
Reverse of the given number = \[837\]
Now, for finding the difference between the two, we subtract the original number from the reverse because the reverse is bigger than the original number and we have:
Difference = \[837 - 738 = 99\]
Hence, the difference between the number\[738\] and that obtained on reversing its digits is \[99.\]

3) Now, given number = \[95,47,999\]
Principle of carry-over:
When we have to find what comes after a number (let the number be x), we simply add 1 to x. But we have to keep in mind that there is a possibility of carry-over. To check for the same, we just have to see if the unit’s place of x is 9. If it is, then the carry-over will occur, else it will not. So, we add 1 to x, if its unit place is 9, we make it 0, and add 1 to the ten’s digit; and we keep on checking, adding 1, making that digit 0, adding 1 to the next digit and so on and so forth till we encounter a number which is not 9 and we add one for the last time and stop there.

So, we add one to the number and apply the principle of carry-over as mentioned above and get:
\[95,47,999 + 1 = 95,48,000\]
Hence, the number which comes just after \[95,47,999\] is \[95,48,000.\]

Note:
For calculating such questions, the fundamentals of the basic concept should be clear. One must know how to approach a question and then it is nothing more than a cake-walk. And one thing to remember is that it is always advisable and sometimes necessary to write down the complete steps so as to make sure the student knows the thing inside-out.