By default it is in mils (1/1000 of an inch) thus the trace is large and it uses exponential notation:
This is telling you for one oz copper and a 1in trace length on the top layer you need a trace width of around 1.3 inches or if you switch to mm
trace width of 33 mm which may be easier to read. Changing to 2oz copper cuts this in half. Lowering the length of the trace will also make it less.
What Fritzing version? It looks like 0.9.3b (and this is 0.9.4 pre release, but 0.9.3b works the same) ?
Ah! You need to click on top (or another modifiable field) in inspector to make the change take (I do that without thinking about it and forgot to mention it the first time):
make the change circled in red then click on the blue circled icon to make the change take effect and you should be away. As a bonus this appears to work correctly in the gerber output (although that may mean the fix is in 0.9.4 and not in 0.9.3b so check your gerber output before ordering boards!)
You are most welcome. That is how I (and most everybody else) learned Fritzing, (because there isn’t a lot of documentation), by asking here. I’m paying forward lots of help from folks no longer posting here from years past. As well other folks will read this and learn how to do this.
edit:
For traces this large, you may well be better to use a copper fill. That said, I know very little about setting up copper fill, but some of the other folks here do.
Peter