Which of the following statements about the number line is true?
a. number lines end with the number 10. b. numbers get smaller as you move to the left on the number line. c. numbers get larger as you move to the left on the number line. d. number lines can't you compare numerals.

The correct answer is B - Numbers get smaller as you move to the left on the number line.
This is true because as you move farther to the left, the numbers become smaller and eventually move into the negatives.

A is incorrect because no number line has a distinct ending. C also is incorrect because the numbers do not get larger as you move in the direction of the "smaller" numbers. Lastly, D is an incorrect option because number lines are often used to compare numerals.

Do you mean conversion factor?