Children packed into their desks and prepared themselves for another day of school. Ms Bitters loomed over them as they took their seats preparing herself for another day of having to teach the little wretches, each one of them, she observed, doomed to failure.

After most of the kids had settled, Zim silently entered the classroom. Robotic eyes scanned the room analyzing the surroundings and students. Dib glared at the green one with his usual gleam of hate. Just as Zim had predicted, nobody noticed that this figure standing before them was the decoy.

"So you decided to show yourself after your dreadful failure yesterday." Bitters address the imposter. "Let's hope you keep it in mind during today's lesson."

"Yes Ms Bitters." It responded alertly, standing straight, remaining motionless before the teacher awaiting a new command.

Ms. Bitters looked questionably at Zim as he stood there, his lack of movement to his desk quickly annoying her.

"Take your seat Zim." She commanded.

The decoy turned its head where the teacher had pointed; Zim's empty desk in the far right corner of the first row. It turned back with a quizzical look on its face.

"Where Ms Bitters?" it asked.

"Excuse me?" She snapped slightly befuddled.

"My desk, where shall I take it?"

A few childish giggles rose from the class as the decoy smiled goofily awaiting an answer.

Ms. Bitters was not amused, she would have yelled at Zim or made him feel some form of doom-laden punishment, but the bell had rung and there was a lesson to be taught. She would have to deal with him later.

"Sit down Zim." She growled "This is no place for humor."

"Yes ma'am." It turned and stepped lightly to the desk. Dib watched carefully and curiously as Zim sat and faced the front board in his usual fashion. Why would Zim make such a stupid remark, the boy wondered. Was he making some pathetic attempt to be funny? Whatever the reason, it wasn't getting the alien in Ms. Bitters' good graces, that is, if she had any to begin with.

"Now today children," the ancient educator began while writing on the black board. "We will be learning math with fractions, and don't go telling me that you don't need to because you have computers. One day all the computers in the world will fail to a terrible virus. And where will you be then? You'll all be doomed! So listen up while I teach you how to find the common denominator."

She wrote a complex equation on the board. The class stared at the growing amount of mixed numbers surrounded with pluses, parenthesis, and division symbols. They all knew that this was far too advanced for their grade but not one would argue with the cold- hearted teacher that was writing it.
Dib glanced over to Zim's desk and was surprised to see the E. T. focused steadfastly on the front board. Usually Zim never paid attention in math, he would always laugh and claim how inferior earth mathematics were and spend the rest of the lesson doodling in his in his notebook or playing with his pencil.
Today was different and somewhat unusual. Not only was Zim paying attention to the utmost fullest, but he was taking notes as well. Every word the teacher said he recorded down on paper with impressive speed and accuracy. Making this feat even more surprising was that he didn't look down at his paper once! Dib couldn't believe his eyes; he removed his glasses and cleaned them just to be sure. Did this mean that there was something this "advanced" alien didn't know? Why else why would he be so interested? The junior paranormalist's thought was derailed when Ms. Bitters addressed the class.

"Alright class," she began "If you have ten and three fifths times twenty tenths divided by six and four fifths equaling six thirtieths what is the lowest common denominator?"

Dumbfounded, the class was silent. A collective thought of "what the hell?" filled all minds. One hand raised.

"Yes Zim?" Bitters acknowledged.

"The lowest common denominator is five."
Silence, this time from shock, even Ms. Bitters was amazed.

"That's... right Zim."

The decoy smiled, his computerized brain enhanced with the best of irken computing technology had made the problem quick and easy. Ms. Bitters turned back to the board.

"Why don't we see if you urchins can figure this one out."
She scribbled another equation, screeching the chalk every few moments, then turning back to the class.

"If you have twenty fiftieths and eight fourths times two point five, what is the common denominator?"

Again only one black gloved hand raised.

"Yes Zim."

"The lowest common denominator is 2" The decoy answered calmly. He paused, "and the answer is 6."

Bitters glanced back at the board, then looked back at the smiling green student amazed and slightly annoyed.

"Right again Zim, but let's not get ahead of ourselves."

"Yes ma'am." He answered back.

"Well, it's nice to see that my words yesterday finally sank into your otherwise empty head and you've taken your studies seriously Zim." She turned to the rest of the class. "Now if only the rest of you could find that kind of enthusiasm there my be an actual chance, despite how small it may be, that you may be able to make something of yourselves."

The children glared at Zim, some confused that he was getting all the answers right, others angry that he was making them look dumb. He looked back at them smiling; unaware he had upset them in some way. The real Zim would be happy to hear that his decoy had made him look smart in class. The smile widened, and none were more suspicious of it then Dib.