Shifting Digits

Q.

How many digits are in between 500 and 600 which have only one 9 in them?

Q.

Write the greatest $5$-digit number in figures and words.

Q. 4+7+2=281435
7+3+9=212781
6+2+7=121456
2+8+5=164036
8+4+6=?????

Q.

Which is the largest of ?

Q. write the smallest 7 digit number using only one digit in Hindi

Q.

Compare the numbers and put the appropriate sign (< / > ) :

91, 62, 00, 008 ____ 916, 000, 000