# decimal form of a unit converted answer

I was wondering what a good way might be to get a decimal answer when using units. For example, say I try

```
#define units
ft = units.length.foot
m = units.length.meter
#add some lengths and output in ft
(3*ft + 4*m).convert(units.length.ft)
```

I get back

```
6143/381*foot
```

Now, suppose I'd rather see this represented as a decimal than a fraction (for homework, perhaps?). If I try

```
(3*ft + 4*m).convert(units.length.foot).n()
```

I get an error. This is occuring on Sage 4.8 for sure, and I'm pretty sure in Sage 5.0 as well.

Can anyone think of a good solution to this?