What is wrong with my code?

I was disappointed in the exercise to get errors on completion with the solution provided removing the typeof query that I’d put in to comply with the second and third bullet points. Would it not be a better UX in the case to direct the user to what is wrong? In the solution you’ll get NaN if you don’t enter a number in the first parameter which just seems a bit sloppy

If that is what you are after, its exactly what the forum is for. We can help with each step, point out why or where you go wrong