Those 5's you have circled in green represents the maximum score you can get for answer those questions correctly. And, since in this case you have at least six questions with five, that adds up to at least 30, which will case the contribution of each question to be scaled.
Simple demo...got to https://qa.moodledemo.net/my/ and log in as teacher using password of test. Once logged in go to the Miscellaneous > Activity examples course. Scroll down to the Quizzes topic and click on, A listening quiz and preview the quiz. Notice to the left in the details for question 1 that it is to be marked out of 1.00. Mark French as the answer and Check it. Finish the attempt. Notice Question 1 is receiving Marks = 1. Submit all and finish. On the review attempt notice Marks is 1 but the Grade is 10 out of 10.
Click on A listening quiz again, then the Edit cog and select Edit quiz. The place where you have 5 in your picture is currently showing a 1. Change the 1 to a 5, or 15, or 50, etc. Let's try 50. Take the quiz again, and make sure you still answer correctly. Watch the same places again. You will get the maximum marks, but the Grade will be scaled to 10.
Delete all the attempts and add a T/F question with maximum of 5, take the test twice again. Answer one correctly and the other incorrectly and notice how the grade is scaled to reflect the total of those maximums. The results with one 50 and one set to 5. i.e., with 50 correct and 5 incorrect gives a grade of 9.09. Vice versa 50 incorrect and 5 correct gives a Grade of 0.91.
Basically, the numbers you have circled in green allow you to make some questions affect the quiz final grade, more than others.