Today I am sad for two reasons:
1. On this day, June 30, my late husband would have turned 47 years old; he died when he was 43 in a motor accident. Of course, I still miss him. He was really a loving and caring person.
2. There are so many misconceptions being taught to students in Mathematics classes. Therefore, we have to help the world fully grasp the beautiful concepts of Mathematics.
One of the misconception that is currently being taught is that "two negatives make a positive", which is to say two negative numbers used in any operation will equal to a positive number. This is not entirely true. Yes, two negative numbers will give a positive number when multiplied or divided. However, if those same two numbers are added or subtracted, the result will vary because it depends on the value of each number being used in the mathematical operation. Let's look at some examples:
-6 x -3 =18 and -6 ÷ -3 = 2 The results are positive
However,
-6 - (-3) = and -6 + (-3) =
-6 + 3 = -3 -6 - 3 = -9 The results are negative
Also,
-6 - (-9) = and -6 + (-9) =
-6 + 9 = 3 -6 - 9 = -15 The results are mixed.
or or
9 - 6 = 3 -9 - 6 = -15
As you see it is very important to teach students especially small children in their formative years, the correct mathematical concepts. If this is not done, then they will be misguided and possibly confused for a long time - sometimes for an entire lifetime. Therefore, instead of broadly saying 'two negatives give a positive' it is better to say When two negative numbers are multiplied or divided the result will be a positive number.
Let's share and care and build each other up in this Mathematical world.
