我怎样才能在最后实现总得分（时间表测验）

I'm trying to create something to test my brothers time's tables. Here is what I have so far.... I really would like to add at the end something that totals up the score Like 12 out of 12 correct or what ever But I have no idea how to do this I have tried Google but If you don't know what your looking for it can be quite tricky to find something.I'm trying to create something to test my broth