ONE evening when I visited St. Petersburg in the summer of 2001, I struck out on my own to find a restaurant mentioned in my three-year-old Rough Guide guidebook. I went on the subway three times, took an electric tram as recommended by natives, asked many people for directions, bought and ate a Super Snickers to relieve immediate hunger, and eventually stopped in at a restaurant that looked established.

A waitress recognized my hungry, bewildered tourist face and asked, "Kushat?" ("To eat?") I nodded and was seated.

The recorded music cheered me — even the Russian Backstreet Boys clone — and the people seemed happy and lively. It turned out to be relatively fancy and tourist-friendly, although the service seemed slow. After telling the server, "Ya ni yem myasa, riba, ili ptitsa, chto vui rekommenduyete?" ("I don't eat meat, fish, or birds — what do you recommend?"), I ended up with a surprisingly good meal of spaghetti with mushrooms, washed down with two smallish glasses of mineral water.

But I had second thoughts that grew along with the empty space on my plate. Hadn't there been two columns of prices on the menu? I remembered one of those numbers being much higher than the other. One said that my dish was 90 rubles, which was about three bucks. The other had displayed the figure "260" — and I didn't have 260 rubles on me! I had "hard currency" (U.S. dollars), but it was illegal to use anything but rubles to buy things in Russia.

My mind raced:

"Food usually doesn't cost more than $5 per entree in Russia! But this is a pretty fancy place. And maybe it's like in some museums, where foreigners have to pay much higher prices than natives. Wait, I saw credit card logos on the door, which had convinced me that this is a reputable establishment. Was the logo of my card up there? I don't remember! There was a menu on the door, too. Would it be OK to look? I'd have to get up and go to the door. There's a guy who looks a little authoritarian sitting by the bar. Maybe he'll come after me if I look like I'm trying to escape paying the bill, or if I try to pay in hard currency. What do I do?"

Finally, I got up and walked a few steps to look at the menu again and breathed a sigh of relief. The column on the left was marked, not "rubles," but "grams." It was telling me the mass of the entree.

I finished my meal, paid about $4 plus a tip (which they say you don't have to do in Russia), and left. I changed $20 into rubles on my way home.

A few months ago, to celebrate my new job and commemorate leaving San Francisco, I shared an evening at a sake bar with my friend Joe. Why not the daiginjo, the fancy sake I'd read about in the booze section of my local newspaper? And sure, a bottle instead of a few glasses would be fine.

The server started treating me very, very nicely. She chatted me up and gave me a flight of comparison sakes so I could understand the subtle grace of the daiginjo.

You can tell where this is going. Yes, the tiny number on the menu that I had thought indicated "milliliters" or "ounces" in fact indicated "dollars." Fortunately, I was well-off enough that this incident only put a big dent in my leisure budget. I put it on my credit card, carried the mostly-full bottle home very carefully, and took it to a party as soon as possible to make sure that this reminder of my foolishness would sully my home no longer.

Of course, my deep and abiding shame lasts to this very day, even as I hope to exorcise it by telling all six of my readers about the time I spent ten times what I meant to on a bottle of sake.

The symmetrical display of innumeracy in these two anecdotes astounds me. Given that I've now experienced both sides of this price/measurement confusion, I hope the universe has finished teaching me to pay close attention to restaurant menus. But who knows what new wrinkle New York may bring?

Sumana Harihareswara writes each week for Bay Area Living. You can send her a note at sumana@crummy.com.