Order of Operations: Negative Sign, Parenthesis
Date: 8/25/96 at 10:6:23 From: Doug Young Subject: Meaning of Negative Sign, Parenthesis Dear Dr. Math, Every school year my students have a hard time seeing (-2)^2 = 4 and -2^2 = -4. They do not see the need for the ( ) and see -4 as a negative number taken to the 2nd power. I have tried to show them -1 * 2^2 = -4 is what is being stated when they see -2^2 = -4. Any suggestions? Thank you, Mrs. Young.
Date: 8/25/96 at 15:30:58 From: Doctor Robert Subject: Re: Meaning of Negative Sign, Parenthesis I think that all students have trouble with this one. You have shown them that -2^2 means -1 * 2^2. What you need to convince them to do is to use the ORDER OF OPERATIONS correctly. The exponent must be dealt with before the multiplication by -1. This is not a law of God, but an international agreement among mathematicans. Good luck. -Doctor Robert, The Math Forum Check out our web site! http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994-2015 The Math Forum