Most ATMs require that you enter a four-digit code, using the digits 0 to 9 . How many four-digit codes are available? codes

Step 1 ：This problem is about permutations with repetition. We have 10 digits (0 to 9) and we need to form a 4-digit code. Each digit can be repeated in the code.

Step 2 ：The total number of codes is calculated by raising the number of possible digits (10) to the power of the number of digits in the code (4). In mathematical terms, this is represented as \(10^4\).

Step 3 ：Calculating \(10^4\) gives us the total number of codes.

Step 4 ：Final Answer: The total number of four-digit codes available is \(\boxed{10000}\).