a. Which is greater, 2 or 4?
On a number line, 2 is to the left of 4, so 2<4 or 4>2.

b. Order these integers form least to greatest. 2, 1, 4, 0, 3, 2, 5
Think of these numbers on a number line in order form left (least) to right (greatest)
5, 4, 2, 0, 1, 2, 3 