How do write 400,000+30,000+800+20+5 in standard form

this would be in the imperative mood. it is a category of verb forms that are used to express orders,instructions,commands or requests.

no its not a run on sentence however i think you meant wet suits not sours also a run on sentence would be like surfers surf all winter long in southern california by using wet sours to keep them warm and the live their all year long  

it is the background information on the characters and setting explained at the beginning of the story. the exposition will often have information about events that happened before the story began. the exposition is often the very first part of the plot.