1. two hundred and seventy eight.
2. five, two hundred and forty five, four hundred and fifty six.
3. one thousand.
4. one hundred.
5. one thousand two hundred and fifty six.
6. если это дробь, то three point three hundred and forty five, а если это тысяча, то three thousand three hundred and forty five.

Ответ:

1) Two hundred and seventy eight

2)five,two hundred and forty five, four hundred and fifty six

3)one thousand

4)one thousand and two hundred fifty six

5)three thousand and three hundred forty five