Pluses and minuses in multiplicationprint resource
Posted by: Laura Avram
Theme: Math;teaching Age Group: 6-12 Date Added: October 15, 2011
What happens with + and - in multiplication .
Students learn what happens with + and - in multiplication .
Pluses and minuses in multiplication
(-x) * (-x) * y * y is positive
(-x) * (-x) * (-x) * y * y * y is negative
However many positive numbers we multiply, the result will be positive, so the number of y – es does not matter.
When multiplying an even number of negative numbers, the result is positive as well. However, when multiplying an uneven number of negative numbers, the result is negative (a pair of minus signs even each other out and result in a positive sign; since an uneven number cannot be divided by 2, there will always be a negative sign left over which will make the whole product negative.). In the second equation we have an uneven number of negative numbers (3), to the result of the product of the x – es is negative, which multiplied with the positive result of the product of the y –es which make the whole result negative. (negative times positive leads to negative)