standard_description: Understand a rational number as a point on the number line. Extend number line diagrams and coordinate axes familiar from previous grades to represent points on the line and in the plane with negative number coordinates.
problem_activity: A biologist is tracking the location of three different animals. On the first day of spring, the biologist records the following information about the three animals:
The first animal is located
$$220$$
m below sea level.
The second animal is located at an elevation of
$$0$$
m.
The third animal has an elevation of
$$−10$$
m.
a.   Draw a number line and represent each animal’s elevation on the number line.
b.   Name a possible animal that could be at each elevation.


aligns: no