Above, the sequence of leaves on a pear tree. If we tie a thread around where one leaf appears on the tree and turn that thread around the branch until coming to the leaf above at the level of the first, we pass by five leaves. We see that only the sixth leaf is at the level we started at and that at this point the thread has run twice around the branch. Therefore, in order to describe how there are five leaves in two circuits, we may write the leaf sequence on this branch as 2/5.