I was sitting at home watching T.V. when a knock came at the door.  I turned off the T.V. and opened the door.  On my porch stood a man wearing a drab, old business suit.

“Good day, sir!” said the man.  “May I take a few minutes of your time?”

Sensing a sales pitch coming on, I said, “Uh, I'm kind of busy; I've got to get back to making sure Coily hasn't taken the springs out of my couch.”

“Please sir, it will only take a moment,” said the man.

I sighed and said, “I can give you five minutes.”

“Thank you sir, you won't regret it!”

The man set down the case he was carrying and opened the top flap.  He pulled out a square rack with ten rods, each strung with ten beads.

“This is an ababcus,” said the man.  “But not just any abacus; it's special.”

“Will it do my taxes?” I asked.

“It can,” said the man excitedly, “but what makes it so special is that it will do the math for you!”

“Huh?” I said.

“Allow me to demonstrate,” he said.  He held up the abacus before continuing.  “Go ahead and ask it what the sum of two numbers is.”

“You mean like, 'What's two plus two?'” I asked.  As soon as the words had left my mouth, all the beads shifted to the left, then two of the bottom beads slid to the right, followed a half second later by two more.

“Wow, nice trick,” I said.

“Try again,” said the man.

“What's six time seven?” I asked.

Again, all the beads clapped back to the left, then several beads clicked back and forth as the abacus automatically made the calculations, until it settled with two beads on the bottom rod and four beads on the next rod up.

“Forty-two!” announced the main.  “Now try something more advanced!”

“Okay,” I said, “What's two to the 64th?”

All the beads clacked back to the left, then beads clacked left and right as two multiplied by itself 64 times was calculated.  After a minute, the beads began moving faster, then faster, and faster.

The man's face took on a worried look, then wide-eyed fear as the beads moved too fast for the the human eye to follow.  He looked like he wanted to drop the abacus, but something compelled him to grip it tighter as it vibrated in his hands.

I stepped back and put my hands over my ears as the noise of the clacking beads became unbearable.  Then suddenly the man and the abacus disappeared in a burst of light and smoke.

I lowered my hands and stared at the vacant scorch mark on my porch for a few seconds then said, “I guess it can't handle overflow.”