Unit 4 Lesson 6 level 4 uses MOD. In my opinion, the math there is way too complex. Then in Lesson 7 level 11, they basically introduce and explain the concept. This doesn’t make sense to me. Also, in this level, the examples they have them test aren’t very good because all of them either have a remainder of 0 or are examples like 2%3, where the remainder is the first number, 2. There should be more examples like 17%5, so they can understand why this is 2.