1. This number has 4 digits 

It is smaller than 6000 but bigger than 5000

The hundreds digit is smaller than 6 but bigger than 4

The tens digit is an odd number smaller than 7 but bigger than 3

The ones digit is in the 3 times tables and is bigger than 6 but smaller than 10

2. This number has 4 digits 

It is smaller than 7000 but bigger than 6000

The hundreds digit is smaller than 7 but bigger than 5

The tens digit is an even number smaller than 5 but bigger than 2

The ones digit is in the 5 times tables and is bigger than 4 but smaller than 9

3. This 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