You can model 1/2÷1/6 on a number line. The red oval has a length of 1/6. How many ovals can you drag onto the number line from 0 to 1/2 without gaps or overlaps? What does this tell you?

Step-by-step explanation:

You can fill in the space between 0 and 1/2 with 3 ovals that are of length 1/6.

This tells you that 1/2 ÷ 1/6 = 3.

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.