Homework

Any listings below are tentative and not intended to be taken as otherwise.





 Earth 911 


http://periodic.lanl.gov/default.htm



A Summary of Rules for Integers

(Actually, for arithmetic with all rational numbers¡K)


We want to eliminate subtraction much of the time by using the additive 
inverse process where we change the subtraction symbol to addition AND 
reverse the sign of the number immediately following.

	Ex. 5-7 would be 5+(-7)

Addition

If the signs (positive and/or negative) are the same then the sum will carry 
the same 
		sign.
	Ex. 	 +2+(+3)=5
		-5+(-7) =-12

	If the signs are not the same, we must look to the absolute value of 
each number (that is to say, the 
		distance from 0 on a number line). The sum will carry the 
sign of the number with the
		greater absolute value. The just find the difference.

	Ex. 	6+(-8)
		6 has an absolute value of six; -8 has an absolute value of 
8 so the sum will be negative
		The difference is 2 so the sum is -2

Multiplication/division

	If both factors are either positive or both factors are negative, 
then the product (same for division).
		is positive.

	If  one factor is positive and one is negative (same for division),  
then the product is negative.