What happens when kids don't get it? As teachers, we are called to meet each kid where they are and bring them as far as they are capable of going. But as we are bringing them along, are we sure, we aren't leaving them behind, bewildered by the lack of support and guidance from the teacher who has handed them a failing grade. When students don't get it, what clicks in your mind?
For me, when I am analyzing student performance, I mentally go through a flowchart of instruction.
Was the concept introduced conceptually? If yes, what strategies were developed, discussed, and implemented to allow the student(s) to gain understanding? If no, how can I guide students to begin to look at the content conceptually?
What methods, have I used to meet the students needs? Have I tried more than one way? If not, TRY ANOTHER WAY.
When students don't get it and you find yourself using the same method every day for several weeks, there may be a flaw in your method. If what you've tried doesn't work, it is okay to say, "what I thought would be effective wasn't, here's how I will change what I did". This is why collaboration is so important. You have the opportunity to bounce ideas off of other teachers. You find out what was effective or ineffective with their students.
Like, shoes, clothes and underwear, education is not one size fits all. Math especially is not one size fits all. So if you have a one size fits all approach to teaching mathematics, consider the flowchart approach of reflection to ensure that when kids don't get it, you've done all you can do to ensure they can. And chances are if you have, they will never receive an assessment with 6 out of 24 correct.