How many four digit numbers are possible if the pin cannot begin or end with a 0 and the PIN must be a even number?

To form a four-digit PIN that does not begin or end with a 0 and must be even, the first digit can be any digit from 1 to 9 (9 options), and the last digit must be an even digit (0, 2, 4, 6, 8), providing 5 options. The second and third digits can be any digit from 0 to 9 (10 options each). Therefore, the total number of valid four-digit PINs is calculated as: ( 9 \times 10 \times 10 \times 5 = 4500 ).