Adding and Subtracting Negative Numbers

Look at how each calculation lays out as a walk along the line. Starting at -3 and adding 5 sends the marker five places to the right and lands on 2. Starting at 2 and subtracting 7 sends it seven places to the left and lands on -5. Subtracting a negative reverses direction once more, so -5 - (-4) lands on -1.