`from_number` is mostly used for the Amount math functionality I believe. That whole block of functionality will need review in the future, but it does support a ton of very subtle functionality, so we will have to be careful about changing it.

``` js
var amt = Amount.from_json('1/USD/[address]').multiply(Amount.from_number(2));
amt.to_text_full();
// returns '2/USD/[address]'
```

Probably `multiply` and similar methods should accept a numeric parameter straight up, which I think would take the primary use case away for from_number.

For multiply the currency doesn't matter, which is probably why this weird behavior was tolerated, I agree with the change.

One thing I don't understand: The currency "1" is hex `0000000000000000000000000000000000000001`, meaning the type byte is zero, which is *not* a demurrage currency.