Sal Khan, Monterey Institute for Technology and Education
Multiplying and dividing positive and negative whole numbers, understanding place value, and rounding numbers. Source: Khan Academy (www.khanacademy.org), used under the Creative Commons Attribution-NonCommercial-ShareAlike (CC BY-NC-SA) license. All Khan Academy content is available for free at www.khanacademy.org. Khan Academy does not endorse the World Public Library.
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