https://www.mathsisfun.com/numbers/decimals-multiplying-animation.html https://www.khanacademy.org/math/pre-algebra/decimals-pre-alg/multiplying-decimals-pre-alg/v/multiplying-decimals
http://www.math4children.com/games-k-to-6/5th%20grade/multiplication/index.html
http://www.math4children.com/games-k-to-6/3rd%20grade/division/index.html
