NEW YORK (MainStreet) — When a waiter trots over to a table full of twentysomethings, holding the bill for their group meal, he carries with him an object of incredible angst.

Case in point: the dinner I recently had with a group of five compatriots, all of us upwardly mobile and overly educated. Throughout the meal, we’d been mildly boasting about our accomplishments and fawning over each other’s talents. By the time we indulged in some chocolate mousse, everyone was riding pretty high on the hog.

But when the $116.37 check arrived, the night’s buoyancy disappeared. We spent no fewer than 15 minutes scribbling and squabbling, trying to sort out what each of us owed for the night’s vittles. We eventually paid appropriate amounts and acted like nothing happened, but the shame was palpable.

How is paying a group check still a problem in 2013? How can it be that this generation of tech-savvy, smartphone-wielding early adopters still boggles at the end of a meal?

Two diners is fine, possibly even three, but if the table’s population gets any bigger, it’s like a social collapse in a rat colony: chaos unfolds as we all turn on one another. There’s the collective “daaaaamn” at the total price, there’s the failed attempt to split the amount evenly, there are the passive-aggressive reminders that so-and-so had one more drink than everyone else, there’s the silent groan of frustration when a couple announces that they’ll be paying as a unit, and so on. Pity the poor server, who has to hear a three-minute explanation of what to do: “Put $17.30 on this credit card, $4.75 on this one-- oh crap, we did the math wrong; give us a moment…”

You’d think there would be an app to easily rid us of this nightmare. If only you were right.

Social payment apps like PayPal and Venmo can, theoretically, make things easier by letting youngsters instantly reimburse each other. One person could pay up front, and everyone else could send him or her money with the tap of a finger. But all the diners would have to be signed up for those services -- and social payment doesn’t touch the problem of doing the math to find out what each person owes.

There are check-splitting apps that try to ease that numerical burden. Billr, Divided, Check Split, Divvy -- they all help sort out group bills. Divvy even lets you enter your data simply by taking a photo of the check. But that leaves the payment problem untouched: even if a program is doing all the math, there will still be a mélange of debit cards, credit cards, and unbroken $20 bills to sort through. These apps are a great start, and we should all download them, but there’s still one more step we all need to take. And it’s astoundingly low-tech.

We need to have a decent amount of paper money with us. All the time. Period.

More often than not, what truly sinks these payment situations is the lack of a common medium of exchange. When cards mix with cash, the amount of necessary calculations skyrockets and errors become harder to fix. Each card becomes its own bill, with a charged amount separate from the other cards and the pooled cash. Errors become harder to fix -- when we inevitably over- or underpay, we end up doing a second round of payments to one another. Or, worse, we just promise to pay each other back later.

But with the magic of cash, everything becomes easier. Pop the meal into one of the check-splitting apps, then have everyone shell out the exact amounts owed. Easy peasy. Don’t let anyone get away with that lamest of excuses: “I only have a twenty.” Force anyone who says that to go to the register and get the $20 bill broken -- and to get an individual dollar broken so that he or she can have exact change. It costs nothing more than a walk from one’s seat.

Even if you don’t believe in collective action, wielding cash and a check-splitting app can still improve your own group-dining experience. Just whip your phone out, quickly calculate what everyone owes, pay your amount and then let the rest of the rats fight it out over their plastic.

Take a bathroom break while they’re doing it, if you want to. Hell, you can even mosey to the bar and pay in cash for one last drink. Say goodbye to all that angst and say hello to self-satisfied schadenfreude. It goes great with any cuisine.