The number has 4 digits. The hundreds digit is the number of sides of a pentagon. The thousands digit is the same as 20/5. The tens digit is more than 0 but less than 2. The ones digit is the same as 20-17.

The number has 4 digits. The tens digit is the same as 8-8. The thousands digit is seven more than the tens digit. The ones digit is the number of sides of a square. The hundreds digit is the same as the tens.

13x13

The number has 4 digits. The thousands digit is the same as 18 divided by 2. The hundreds digit is the same as 90 divided by 10. The ones digit is the same as 3x3. The tens digit is the same as 100-91.

7x7

The number has 4 digits. The thousands digit is the number of days in a week. The ones digit is half of 12. The tens digit is the number of wheels on a bicycle. The hundreds digit is 2 less than the ones digit.

5x5-10

6x9

The number has 3 digits. The ones digit is 82 less than 91. The hundreds digit is an odd number which is bigger then 1 but smaller than 4. The tens digit is the same as 6+3.

The number has 3 digits. The ones digit is double four. The hundreds digit is an even number bigger than 5 but smaller than 7. The tens digit is half the ones digit.

The number has 3 digits. The tens digit is less than 1. The ones digit is the number of sides of a triangle. The hundreds digit is the same as 10-3.

14x14

4x4-8