Question

Claire draws a vertical number line diagram and graphs two points: −10 and 10. She writes the following related story:

"These two locations represent different elevations. One location is 10 feet above sea level, and one location is 10 feet below sea level. On a number line, 10 feet above sea level is represented by graphing a point at 10, and 10 feet below sea level is represented by graphing a point at −10."

Determine if you agree or disagree with the representation. Then, defend your stance by citing specific details in your writing.

Answer 1

I agree with Claire's representation. Sea level is considered as zero, going up in the number line is positive and going down in the number line is negative.

The location 10 feet above sea level is correct. We have to count 10 spaces going upwards from zero. This location is represented by the integer 10.

The location 10 feet below sea level is correct. We have to count 10 spaces going downwards from zero. This location is represented by the integer -10.

Explanation:

The attached picture shows two points:

The red point represents 10 feet above sea level. (Integer: 10)

The blue point represents 10 feet below sea level. (Integer: -10)

Sea level is zero.