These lines look pretty different, don't they?

Lines are used to keep track of lots of info -- like how much money a company makes.  Just off the top of your head, which of the lines above would you want to describe the profits of YOUR company?  Whether the line is tilted up or down, all of the sudden, gets REALLY important!

I am now going to introduce you to

Pierre The Mountain Climbing Ant

(He's kind of a pathetic math super hero.)

For slopes, Pierre is going to walk on the lines from left to right
 -- just like we read.

Uphill slopes are positive slopes.
The slope will be a positive number like 5 or 2/3.

Downhill slopes are negative slopes.
The slope will be a negative number like -7 or -1/3.

There are three ways to find the slope of a line.  Two of them are in the next two lessons and the third comes later.