please help me, create an algorithm that can be used to spell out a positive number worth less than 1,000,000 and create a c ++ program for the algorithm

is this a

Please do my homework for me

post? then, no. first, be clear in what you are looking for.
secondly, don't post C++ questions tagged with Java.

but, just to help you out, I'll give you an implementation in pseudoCode:

call spellOutAPositiveNumberWorthLessThan1000000

: spellOutAPositiveNumberWorthLessThan1000000
  => return 75000000

For me, personally, 75000000 is worth less than 1000000, because it isn't used quite as often. See where being vague might lead you to unexpected results?