I have had to reteach my DD6 math but for a different reason. She knew how to do add/subtraction when she went into K but when they taught it to her in school. They taught the concept using a number line. My DD is a sponge so we had to work to fix that problem.
And now this year in her "accelerated math" class they are teaching her to count coins by counting by 5's!
5 counts for the qtr & 2 counts for the dime.
I had to go talk to the teacher because my DD can count change just finein her head.
Counting change by 5's is the silliest thing I have ever heard to teach to ACCELERATED math students.