Complex sentence: The number 0 wants to climb up an apple tree, as the numbers from 1 to 99 climb it in counting order, but there is no room for him and he started to cry.
Split into simpler sentences: The number 0 wants to climb up an apple tree, as the numbers from 1 to 99 in counting order climb it. Since all the other numbers come before him, there is no room for him and he started to cry.