Explain to James that if he wants to have strong wizarding power, he will have to master the proper incantations, hand motions, and wand movements.
Long division is the unraveling of multiplication, which is serial addition. All of these arts stack up on top of each other like Legos.
No one can reach the pinnacle of productivity and become the master of all he surveys if he does not build the proper foundation. It's in the Book.
I actually understood that.