Right now mission are show with their completeness in percent. The porpose of this idea is to give absolute numbers instead of the percent values.
When looking at mission which are build from multiple tasks like 'Java expert' which consists of 25 helpful and 25 correct answers to mission looks like
On the first page the 90% doesn't tell you what is missing and on the detailed page you don't see the actual number too.
To get to the number you have to look at the equivalent single mission
to see the number of correct answers and calculate the missing number of correct answers as 2 to complete the mission.