Thanks La Texican for the link to the Calculus book. I'll give that a try.
Thanks Nautigal for the explanations. I was discussing this with the Psychologist who tested our DS. He mentioned that DS's Visual Spacial Intelligence is the highest of the subsets on the WISC IV and DS uses his Right brain to do all the computations before, but now is trying to learn to use his Left brain.
Thanks CFK, yes we made that BIG mistake... we have quit Kumon as of today! You are absolutely right. He taught himself to read, and had figured out some way to learn math in his own way before we stuck him in Kumon and tortured him for a year with boredom.
As to why we agreed to hold him back: He has severe (life-threatening) multiple food allergies and we didn't feel comfortable enough to let him handle that on his own. Also, he would not focus on his given task in preschool. He would be told to finish coloring his numbers or writing his letters. He could do it in 5 minutes if he wanted to but, he'd dilly dally for 30 minutes and the teacher would hold him from going to recess until he completed it. Plus, we didn't have him tested until 2 weeks ago.
