yes
Six billion.
600 billion.
efef
In the same way as you convert apples to footballs -in other words, you don't!
One point nine
Both of the words convert and converted can be used as nouns. Convert is singular while converted is implied plural: The convert donated to the church. The Rabbi preached to the converted.
0.055 = fifty-five thousandths.
Two point zero eight.
.725 in words would normally be: Point seven two five.
Some words that end with vert are convert, invert, advert, transvert, and divert.