Write the greatest 4 digit number using digits 0,3,7,2

Which is the smallest number when we arranged the numbers 4729,4374,4279,4972 in ascending order.

Write the successor of 9872

Write the smallest 4 digit number using the digit 9,1,2,6

___________,7324,7325,7326

7230_______4921

Write the number comes between 6321 and 6323

Smallest 4 digit number is

Write the predecessor of 4000

2672,2673,________,2675