Scientists on a submarine are investigating Earth's magnetic field.
The submarine is at a depth of -116 2/7 feet when the scientists detect a signal frequency from the ocean floor. They dive farther down to a depth of -180 4/7 feet to check the signal. The net change in their depth is _______feet?

Question

Scientists on a submarine are investigating Earth's magnetic field.
The submarine is at a depth of -116 2/7  feet when the scientists detect a signal frequency from the ocean floor. They dive farther down to a depth of  -180 4/7 feet to check the signal. The net change in their depth is _______feet?

Mercury · Answer

generally to find the net change between two values, you'd simply subtract the two values, and take the absolute value of the result

the fractions make this a bit more complicated.

you could convert them both to improper fractions and then subtract.

alternatively, consider:
the difference between -180 4/7 and -116 2/7 is the same as the difference between 180 4/7 and 116 2/7

so you could subtract

180 4/7 - 116 2/7

using the commutative property:

(180 - 116) + (4/7 - 2/7) = ?