  Math Central - mathcentral.uregina.ca  Quandaries & Queries    Q & Q    Topic: multiplication of negatives   start over

One item is filed under this topic.    Page1/1            Multiplcation of two negative numbers 2007-07-26 From Brett:Someone asked a question about multiplication and division of two negative numbers yielding a positive result here: http://mathcentral.uregina.ca/qq/database/QQ.09.99/butler1.html I was not fully happy with the explanation b/c I want to give me daughter a real-world example and I can't seem to find one. The following illustrates why multiplying negative numbers has become difficult to explain: 2 X 2 = 4 ----(-4)---(-2)---0---2---4 In this example we start with 2 and then want 2 more of them. When we move across the number line from 2 to our answer, which is four, we have moved only 2 units to the right. -2 X -2 = 4 ----(-4)---(-2)---0---2---4 In this example we start with -2 and then want -2 more of them. When we move across the number line from -2 to our answer, which is four, we have moved 6 units to the right. How can the phenomenon of multiplying two negative numbers being more powerful than multiplying two positive numbers be explained? -BrettAnswered by Stephen La Rocque and Harley Weston.      Page1/1    Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.    about math central :: site map :: links :: notre site français