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| This will be our last strip on Common Core for a while, we promise. This is multiplication of 83 x 27. If you do it in your head or on paper the old way you will get 2241. Now let's show Common Core. | |
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| In the Partial Products Method, you multiply 80x20 and get 1600, then 80x7 and get 560 then 3x20 to get 60 and then 3x7 to get 21. Then you add 1600+560+60+21 to get 2241. | |
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| And now we're going to show you the Common Core Lattice Method because we can hardly believe it either but it is true. The lattice method employs a grid of squares. | |
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| One factor is written along the top, left to right and the other factor is written along the right edge top to bottom. Each square of the grid defined by the two factors is divided by a diagonal. | |
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| The digits of the factors are multiplied pairwise, the two-digit result written down in the corresponding square so that the result of the multiplication is obtained by addition down the diagonal. | |
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| We'll leave this alone for now but if you have children learning common core please teach them how to add, subtract, multiply and divide at home. It's only going to get worse. | |
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