Spending time (and calories)

I've been spending some time with the newest member of the family, and have ridden 900 km (around 560 mi) in the last three weeks. I keep trying to figure out if that's a lot or not. I fully recognize that it's nothing in the face of the 3608 km of the Tour de France, but then I think, well that's almost a quarter of the distance of the Tour in the same timeframe, and that in addition to working full time and otherwise living a relatively active and productive life.

I guess it's all relative. It's a fair amount of activity compared to a couch potato, but probably doesn't stack very impressively against more athletic types.

I have a 2003 Mazda Protegé5, and at 9.9 l/100km (my commute is nasty city driving) 900 km equates to around $75 saved in gasoline not purchased. Only 27 more weeks until the bike pays for itself in gasoline savings (although we're not going to mention how much more I'm spending on food...). Someone please tell me if my math is messed up.