Slope is rise over run or the change in y over change in x. So to find the slope count the difference from one point to the next, for example (0,4) and (1,1). In this case, the y-value decreases by 3, so -3, and the x-value increases by 1, so +1. Which would be -3/1 or just -3. One way to visually check is to remember that slopes less than -1 or greater than 1 make the line steeper and negative slopes make the graph decrease from left to right.