you can write that answer a thousand million ways!
As many as you want. An unlimited number of ways.
How many languages can you write......? The answer: a lot (depending on the above question)
There are three ways you can write the number 10. You can use X, as in Roman numerals, ten, or 10.
I can write my name in 100 different ways
As many as you want.
Only one, in terms of numbers: 20,000
500 different ways