If the base case of a recursive function returns a value It would be unusual since recursive functions usually don't return anything. The value returned will always be 0. Then every recursive case must also return a value Then the function is done with its work The ordering of nodes in a binary search tree follows the rule: Items less than or equal to the root go to the left, otherwise they go to the right. Everything but the root is on the left. The most important things go at the top. Items that come first go at the bottom