At a grocery store, a customer pays a total of $11.10 for 1.6 pounds of chicken and 2 pounds of fish. Another customer pays a total of $12.15 for 2.4 pounds of chicken and 1.8 pounds of fish. How much does each cost per pound?

1) on the number line, -1.5 can be seen as going backwards 1.5.
there are -4 groups of -1.5
this means that you have to move in the opposite direction that you would normally move 1.5
4 groups of 1.5 is 6 (because you have to move in the positive direction)
6 is the answer

2) 975 feet below the surface