What is the rule for writing out numerals such as one million five hundred twenty thousand seven hundred and twenty-five? Where should the conjunctive "and" be used -- before the last numeral only?


Please advise how I'm supposed to find your answer? Or will you email it to me?
generally speaking, number up to 100 should be written out as words; all others as numerals. (exceptions to be made for technical manuals, etc.)

as for the conjunction ("and"), the rule is the same for ALL numbers: NEVER use "and" (though nearly everyone does in common speech.)

except when writing a check/bank draft, i have never in my life had occasion to write (or see written) such large numbers in "word" form. (so, if anyone wants to write me a check for 1,520,725 dollars/euros/pounds sterling, what have you, i shall graciously accept it.)

possible exception (sorry... just thought of this one): if a very large number is "round" or exact, it is common to write it as words, or even as a combination of words... 4 million dollars, or four million dollars (the first, it seems to me, is more common.) for "vague" large numbers (ex. "billions and billions" ... i quote carl sagan), of course the words are used since there is no numeric form for these expressions.
Chuckling. You advise writing out all numbers as words "up to 100..." but you elect instead to write one hundred in numeral form. I love irony...

Not mocking...just chuckling...