To help understand decimals I'll give you a little chart. (wherever the one is placed is the name of the decimal):
0.1 = tenths
0.01 = hundredths
0.001 = thousandths
0.0001 = ten thousandths
0.00001 = hundred thousandths
So six hundred thousandths would be 0.00006
Six hundred-thousandths. Could be easily confused with 0.600: six hundred thousandths. (as in "six" "hundred-thousandths" vs "six hundred" "thousandths")
Two and six hundred thousandths in decimal form would be written as 2.00006
Six hundred seventy six thousandths in standard decimal form is 0.676.
The numeral is 6.00409 (the decimal value is 409 hundred-thousandths).
.615
Six hundred-thousandths. Could be easily confused with 0.600: six hundred thousandths. (as in "six" "hundred-thousandths" vs "six hundred" "thousandths")
Two and six hundred thousandths in decimal form would be written as 2.00006
Six hundred seventy six thousandths in standard decimal form is 0.676.
The numeral is 6.00409 (the decimal value is 409 hundred-thousandths).
0.0606
0.676
Well, honey, four hundred and six thousandths in a decimal is 0.406. It's as simple as that. No need to make it more complicated than it is.
Nine and six hundred eighty-eight thousandths in decimal form is 9.688
It is 600.008
0.600
6.00021 The first decimal place is tenths, then hundredths, thousandths, ten-thousandths, hundred-thousandths, etc. 21 hundred-thousandths must end in the hundred-thousandths place.
Six hundred and twelve thousandths is written 600.012