@futurebird I'm not a CS teacher, but I have taught both my kids how to code.

In order to program, you first think both backwards and forwards. For design, you think about what you want, and work backwards from that. For coding, you think about what the present problem needs, and work forwards from that. You imitate the computer in your mind step-by-step to check.

When debugging, it's the same. You think about what happened, and you work backwards from that. What must have been true for that to happen? You can usually find the place where the error must be from that. You might add some code to verify your assumptions. For each piece, you imitate the computer in your mind, forward step-by-step, to find where the divergence is.