standard_description: Apply the properties of operations to generate equivalent expressions. For example, apply the distributive property to the expression 3 (2 + x) to produce the equivalent expression 6 + 3x; apply the distributive property to the expression 24x + 18y to produce the equivalent expression 6 (4x + 3y); apply properties of operations to y + y + y to produce the equivalent expression 3y.
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