Expert: Richard J. Raridon - 5/18/2008

Question
Richard:   One more thing... how can you subtract a negative number anyway?   If you have +7 apples, -4 apples means you don't have any apples.   So if you had 7 apples how could you subtract 4 apples that don't even exist?   This really boggles my mind.   

In the equation -7 -4 the answer would seem to be +28 since they are both negatives and you just multiply and change the sign.
But in the equation -7 - 4 (because the dash does not hug the 4) it means subtract plus 4,-7 -+4 the answer should be either 3 or 11, but not +28.

I have tried to understand negative numbers every time I took basic algebra.   I am now an older adult and have stuggled with algebra four times but cannot get good explanations.  Can you make any sense out of my reasoning?

Thank you.  

Answer
+7 apples -4 apples simply means you're taking 4 apples away from seven, leaving 3 apples.  There's nothing in -7 -4 which tells you to multiply to get +28.  You'd have to write it (-7)(-4) or (-7)*(-4).  -7 - 4 would give you -3.  I don't see where you have a problem but then I'm 76 and have been doing algebra for over 60 years.