The sum of the whole numbers from $$1$$ through $$100$$ is $$5050$$. What is the sum of the whole numbers from $$1$$ through $$200$$? 
Overseas Competition->Knowledge Point->Calculation Modules->Sequences and Number Tables->Arithmetic Sequences
($$1$$ to $$200$$)$$=$$($$1$$ to $$100$$)$$+[(100+1)+(100+2)+\cdots +(100+100)]=$$($$1$$ to $$100$$)$$+[(100\times 100)+$$($$1$$ to $$100$$)$$]=5050+[10000+5050]=20100$$. 