Hi ddon,
You use the BACK of the paper to move from the centre (cross) to the edge (box).
I first learned this as a dot inside a circle (same principle). You begin by drawing the dot (as per normal). Without lifting the pen, you fold over the paper so that the edge of the paper touches the end of the pen. You now draw a line on the BACK of the paper to get you away from the dot.
Once you have some distance between the pen and the dot, you draw a line (still on the back of the paper) off the edge of the paper and begin drawing the line on the right side of the paper a little distance away from the dot. Flatten the paper and complete the circle around the dot.
If this has been carefully carried out, at no point does the pen leave the paper! Yet you are left with a dot within a circle!