



Negative
numbers are weird. 


I
like to think of positive and negative numbers 


like
the floors of a great big building with lots of basement levels ... 











Now
think about adding and subtracting like elevator rides in that
building: 





1)
The first number is the floor where you start. 





2)
The sign that comes after the first number 


says which way the
elevator goes. 


+ means it goes up, 
means it goes down. 





3)
The second number is how many floors you move. 





Example



3  5 











So:
3  5 =  2






Example 





 3 
2 











So:
 3  2 =  5






Example 





 2 + 5












So:
 2 + 5 = 3






copyright 2005 Bruce Kirkpatrick 
