Fred's basement is flooded. The basement floor is
3.43.4
3.4
3, point, 4
meters below the ground floor. The water is
1.21.2
1.2
1, point, 2
meters high.
The following equation describes this situation.
\quad

−3.4+1.2=−2.2-3.4+1.2 = -2.2
−3.4+1.2=−2.2
minus, 3, point, 4, plus, 1, point, 2, equals, minus, 2, point, 2
What does
−2.2-2.2
−2.2
minus, 2, point, 2
tell us?