Nick and I were doing some work with negative numbers the other day, and I turned to Khan Academy for some help. Khan Academy is a library of educational youtube videos made by Sal Khan, who has quit his full time job and created 1600 tablet videos, mostly illustrating math and science concepts.
At his site, Khan explains the philosophy behind his lessons, starting with his discouragement with traditional textbook approaches:
There would be connections in the subject matter that standard curricula would ignore despite the fact that they make the content easier to understand, enjoy, and RETAIN. I felt like fascinating and INTUITIVE concepts were almost intentionally being butchered into pages and pages of sleep-inducing text and monotonic, scripted lectures. I saw otherwise intelligent peers memorizing steps and formulas for the next exam without any sense of the intuition or big picture, only to forget everything within a matter of weeks. These videos are my expression of how the concepts should have been expressed in the first place, all while not compromising rigor or comprehensiveness.
Nick and I used the pre-algebra videos to learn more about negative numbers, but you’ll see that Khan’s lessons cover algebra, chemistry, biology, geometry, physics, calculus, arithmetic, finance, developmental math and more. There’s even SAT prep.
Khan’s website and tutorials are offered as a free resource. Khan says, “I see Khan Academy becoming the world’s first free, world-class virtual school where anyone can learn anything–for free.”
I find that in addition to having potential as a primary learning tool for a kid, the Khan Academy videos provide an easy brush-up for a homeschool mom who just needs to double check: A negative times a negative is a positive, right?