A tortoise is running along a $$5$$ metre track. It can run either half a metre or a metre every second. How many different ways can the tortoise finish the track? 
Overseas Competition->Knowledge Point->Combinatorics->Strategies and Operations->Inductive Recursion
$$1$$,$$2$$,$$3$$,$$5$$,$$8$$,$$13$$,$$21$$,$$34$$,$$55$$,$$89$$ 