odd number of questions to still show 100% completion

Hi,

We previously had quiz questions that have 10 questions which were 10% each, equaling to 100% on completion which made things simple.

We now have 6 questions. How do we make the score percentage round off to an even number of 70, 80, 90, 100% etc?

At the moment it is showing 86.66% for example.

We need the user to score 4 out of 6 to complete also.

Thanks

Dwayne