Add a line and fix the typo

My dad has invented a new puzzle genre called “add a line and fix the typo”, but due to his senility I can’t be 100% sure this was a deliberate effort on his part. Last week he showed me a puzzle and I solved it almost instantly.

The puzzle is shown below: you have to make this equation correct by adding a line and fixing the typo.

Note: I tagged this under "matches" even though the equation doesn't really consist of matchsticks.

The line can be added here to create an inequality; I doubt this is the intended solution.

There's a variant of this puzzle in which the solution is 550, where you turn the "5+5" into 545 with the line, but I'm not sure about 500.

Correct solution:

For those who can't see

545+5=550 (the typo is the first 0 being a 5, not a 0.

• Correct answer, well done! Commented Nov 6, 2022 at 4:27
• rot13(Lbh pna nyfb ghea gur frpbaq cyhf fvta vagb n sbhe, engure guna gur svefg bar). Commented Nov 6, 2022 at 5:29
• @EdMurphy, that is indeed the case... Commented Nov 6, 2022 at 5:37