Grammar question in section 1.11

In lesson 1.1 (Advanced Numbers) in the section "Useful Expressions" there is the example "Wieviel kostes das?" Is this grammatically correct? Shouldn't the phrase be "Wieviel kostet das?"?

Hi Karl, thanks for pointing this out to me. You are of course right, it should be "Wieviel kostet das?". I have fixed the mistake. I apologize for the confusion. Next time you view the lesson it will show the correct version. All the best Paul