I'm not sure if you meant 240.149 as a decimal or a whole number, so I'll do it for both. I'll also add information about the place values so you can see how it's done.
Whole number:
Two hundred forty thousand and one hundred forty nine
200 000 (2 for hundred thousands')
40 000 (4 for ten thousands')
(here we can skip 0)
100 (1 for hundreds')
40 (4 for tens')
9 (9 for ones')
Decimal:
Two hundred forty point one hundred and forty nine
200 (2 for hundreds')
40 (4 for tens')
(skip 0 again)
0.1 (1 for tenth)
0.04 (4 for hundredth)
0.009 (9 for thousandth)
In the word form we just need to read it carefully and we'll surely quickly understand place values of each digit.