Sometimes the idea about subtraction is a little thought provoking.

#color(brown)("Very important fact")#

The natural way to count on the number line is increasingly positive. Often drawn so that it is towards the right. The number line is the same sort of thing as the x-axis on a graph.

#color(brown)("Always think of starting to count to the right on the number line.")#

#color(brown)("The minus sign means change direction of count")#

#+" " -> "Count right"#

#-" "-> "Reverse direction count so you count left"#

#- -" "->"Reverse direction of count twice. You end up" #

#" going in the positive direction"#

#(-2) -># Count to the left

#+(-8)-> # + is count right but the - instructs change direction. So you end up counting left. So this is the same as just #-8#

#+(-6)-> #+ is count right but the - instructs change direction. So you end up counting left. So this is the same as just #-6#

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#color(blue)("Putting it all together")#

#(-2)+(-8)+(-6)" "->" "-2-8-6 = -16#