Write as a decimal number.

a) 4 wholes 25 hundredths =

b) 30 wholes 86 thousandths =

c) 0 wholes 21 tenths of a thousandth =

d) 12 wholes 14 parts per million =

e) 3 wholes 3 tenths =

f) 200 wholes 555 thousandths =