Art of Problem Solving Prealgebra: 'Multiple' Facts

[ethanye]

I’m in this class and need to watch these

[Ms.Amercana]

Richard Rusczyk: "You don't know what's gonna happen, division is just weird."

[jojo]

In the problem: 5. If we subtract one multiple of 7 from another multiple of 7, is the difference a multiple of 7?, (timestamp at the end of the problem 2:10), what if 7 (a-b) is equal to 0? 0 is not a multiple of 7...?

[gaaes]

So... Couldn't we just see that multiplication is repeated addition and see that the product WOULD be a product of x?

[playlist]

Wait... Isn’t division a multiplication of a reciprocal?

[bearbeardoudare]

nice... I love how you are so funny, although you can edit to make it better