Before the KA team tackles aligning to the Common Core Standards, please consider strengthening the multiplication exercises.
I'll be straightforward on this one: Please split "Multiplication 1" into 12 different exercises, ranging from 1x1 to 12x12, under "Multiplication Challenge". I'm trying myself, but I'm still learning how to create exercise modules, so it will take quite some time.
Mastering multiplication is a pivotal step for elementary students. It needs to be second-nature, like knowing your age, when you were born, or your shoe size. There is a drastic dropoff in grades for students who do not master multiplication at an early age. It is a massive barrier to entry for mid and upper-level math. For example, a student labeled 'proficient' in Multiplication 1 may still struggle on Order of Operations becasue of his/her lack of strong multiplication skills. (This happens to many of my students).