12.0905
0.0589
Well, you might add 12000 + 1200 + 12, but that is not the normal way to name this number. Usually you say "twelve hundred" if there are no higher digits.
Seven hundred forty-five and nine hundred twelve thousandths
two hundred twelve thousand, five hundred.
512,000
Either keep the numbers and write 512 or write five hundred and twelve five hundred = quinientos and = y twelve = doce quinientos y doce
Two hundred twelve thousand, five hundred.
Three hundred twelve thousand, five hundred.
two hundred twelve thousand, five hundred
506,712 = five hundred six thousand, seven hundred twelve. 506.712 = five hundred six and seven hundred twelve thousandths.
12.575
£12.05