Answer :
if by standard from you mean numbers (123) and not words then
1 milllion=1000 thousand or 1000*1000 or 1,000,000
1 billion=1000 million=1000*1000*1000=1,000,000,000
so 7billion=7*1000*1000*1000=7,000,000,000
1 milllion=1000 thousand or 1000*1000 or 1,000,000
1 billion=1000 million=1000*1000*1000=1,000,000,000
so 7billion=7*1000*1000*1000=7,000,000,000