Question
A penguin dove to 130 feet below the waters surface. Then it swam up to 48 feet. At what depth is the penguin after it swam up 48 feet?
Answers
Steve
-130 + 48 = ?
Amy
186 ?
Steve
no,
-130-48 = -178
if you think the other way around, the depth started at 130 and then was reduced by 48 as the penguin rose
130-48 = 82
or, as feet from the surface,
-130+48 = -82
Get out your number line, and remember that negative means go left, and positive means go right.
Starting at 0, go left 130 and then go right 48. You wind up 82 to the left.
-130-48 = -178
if you think the other way around, the depth started at 130 and then was reduced by 48 as the penguin rose
130-48 = 82
or, as feet from the surface,
-130+48 = -82
Get out your number line, and remember that negative means go left, and positive means go right.
Starting at 0, go left 130 and then go right 48. You wind up 82 to the left.