Question

grade 7 unit 5: check your readiness (a)
do not use a calculator.
1.
a. a dolphin is at the surface of the ocean. what is the dolphin’s elevation?
b. the dolphin dives 20 feet below the surface of the ocean. what is its new elevation?

Explanation:

Part (a)

Step1: Define elevation at surface

The ocean surface is typically considered as an elevation of 0 (since it's the reference point, like sea level is 0 in elevation terms). So a dolphin at the surface has an elevation of 0.

Step1: Understand direction of elevation

Below the surface means the elevation is negative (as surface is 0, going down is negative). The dolphin dives 20 feet below, so we represent this as -20.

Answer:

0

Part (b)