Draw a graph with an "X" and "Y" axis on a sheet of graph paper. It can have one, two, or four quadrants, depending on the skill level of the students. The "Y" axis is vertical, and the "X" axis is horizontal. They meet at a right angle to form the quadrants.
Label the units. Zero should be where the "X" axis meets the "Y" axis. Then all other numbers should progress sequentially outward. Negative numbers, such as -1 and -2, begin to the left of the zero on the "X" axis, and beneath the zero on the "Y" axis.
Plot your first point. All points must be in the same quadrant, and none must be zero for the box to be floating. The easiest is the upper-right quadrant where both the "X" and "Y" values are positive. For example, (1,1) is acceptable. "X" values are listed first, then "Y" values in this ordered pair.
Plot your second point. Either the "X" or "Y" value must be the same as the first point. For example, (1,4) or (4,1) would be acceptable, but (2,4) or (4,2) would not. For example, (1,4) will place the second point three units above the first. Draw a line to connect the two points.
Plot your third point. If your second point's "X" value was the same as the first point, as in Step 4, the third point's "Y" value must be the same as the first point, and vice versa. For example, (5,1) will place the third point four units right of the first point. Draw a line connecting your first and third points.
Plot your fourth, and last, point. In this case, its coordinates have been decided by the "Y" value of the second point and the "X" value of the second point, making it (5,4). However, if the "Y" value of the second point is the same as the "Y" value of the first, the situation would be reversed. Draw two lines connecting the fourth point to the second and third points. They will meet at a right angle, completing the floating box.