Number Play

1234567
Across
  1. 2. [45,78,92,31,60]which is a supercell in the grid
  2. 4. the total number of 4-digit numbers is
  3. 5. [123, 848, 401,236] which is a palindrome number?
  4. 6. the smallest number made from digit 3,9, 0, 1
  5. 7. the Kaprekar constant for 4-digit numbers?
Down
  1. 1. reserve the digits of the number 2332,then you get
  2. 2. largest 4-digit even number is
  3. 3. how many times does the digit 7 appear when writing all numbers from 1 to 100?
  4. 5. the largest number that can be formed using the digits 6382?
  5. 6. the correct sum of digits for the number176.