I have a hard time remembering which symbol represents a credit. Is it + and – symbols for credit. Here is one idea.

Credit is a – sign. Visually, the – sign. It could look like taffy  being stretched apart or something being  pulled away from is source, thus stretching it until it breaks away from its source. Taking money away or less money is a negative/– credit. The + sign is easier. + Is added or debit.

That might help me.