7. (5 points) If all the digits of a four-digit number are even, and the digit in the hundreds place is 2, then there are $\qquad$ such four-digit numbers.

The number of such four-digit numbers is $\qquad$.
【Analysis】The highest place of a four-digit number is the thousand's place, which cannot be 0, so it can be $2,4,6,8$, and the hundred's place is fixed at 2. Therefore, the ten's and unit's places can be $0,2,4,6,8$. According to the characteristics of permutations, there are $4 \times 5 \times 5$ different four-digit numbers.

【Solution】Solution: The thousand's place can take $2,4,6,8$, and the ten's and unit's places can take $0,2,4,6,8$, so $4 \times 5 \times 5=100$ (numbers). Therefore, the answer is: 100.