Read this word problem. $\newline$ Lake Eyre, which has the lowest elevation in Australia, is $16$ meters below sea level. The Taieri Plain, the lowest place in New Zealand, is $2$ meters below sea level. How much higher is the Taieri Plain than Lake Eyre? $\newline$ To solve the problem, Elise subtracted $-2 - (-16)$ and came up with an answer of $-18$ meters. Is Elise correct? Why or why not? $\newline$ Choices: $\newline$ (A) Yes, Elise is correct. $\newline$ (B) No. The answer should have been $14$ meters, not $-18$ meters, because subtracting a negative number is the same as adding its opposite. $\newline$ (C) No. Elise should have added $-2 + (-16)$ because the Taieri Plain is higher.

Full solution

Q. Read this word problem.

\newline

Lake Eyre, which has the lowest elevation in Australia, is

16

meters below sea level. The Taieri Plain, the lowest place in New Zealand, is

2

meters below sea level. How much higher is the Taieri Plain than Lake Eyre?

\newline

To solve the problem, Elise subtracted

-2 - (-16)

and came up with an answer of

-18

meters. Is Elise correct? Why or why not?

\newline

Choices:

\newline

(A) Yes, Elise is correct.

\newline

(B) No. The answer should have been

14

meters, not

-18

meters, because subtracting a negative number is the same as adding its opposite.

\newline

-2 + (-16)

because the Taieri Plain is higher.

Identify elevations: Identify the elevations. Lake Eyre is at $-16$ meters and the Taieri Plain is at $-2$ meters.
Calculate difference: Calculate the difference in elevation. Subtract the elevation of the Taieri Plain from the elevation of Lake Eyre: $-2 - (-16)$ .
Perform subtraction: Perform the subtraction, remembering that subtracting a negative is like adding a positive: $-2 + 16$ .
Complete calculation: Complete the calculation: $-2 + 16 = 14$ .
Check result: Check the result. The Taieri Plain is $14$ meters higher than Lake Eyre.