週五下廚房week2
週五下廚房week2
腦洞數學 第四週 Fun Math Week 4 日本人發明的魔幻乘法
It’s not magic, it’s maths – how the Japanese multiplication method works https://www.youtube.com/watch?v=85Vd0NpL32k How does the Japanese multiplication method work? In the Japanese multiplication method, we are able to complete a multiplication problem by merely drawing a few lines and counting the points of intersections. Sounds too good to be true, right? Let’s take 12×32 as our example. Remember that numbers are represented using place value: 12 means one ten and two ones, 32 means three tens and two ones. We then draw diagonal lines corresponding to the tens and, after leaving a gap, we draw more lines in parallel to represent the ones (it helps to use a different color). So for the number 12 we get: 日语乘法方法如何工作？ 在日语乘法中，我们只需画几条线并计算相交点就可以完成乘法问题。 听起来好得令人难以置信，对吧？ 让我们以12×32为例。 请记住，数字是用位值表示的：12表示一十和二，32表示三十和二。 然后，我们绘制对应于十的对角线，并在留出间隙后，平行绘制更多的线来表示该对角线（这有助于使用不同的颜色）。 因此，对于数字12，我们得到： ...
