Subtracting larger numbers in your head is not always easy, so you can use the column method to take one number away from another. You write the larger number above the smaller number, so that the ...

NARRATION:Back in the deepest, darkest depths of time, there lived a great mathemagician called Hypatia. Numbers fell under her spell one by one. With them, Hypatia could do anything. Now Hypatia is ...