What is a Function?
Professor P. Explains These Magical Mathematical Machines!
"Do you know what day it is today, class?" asked Mrs. Webber.
"Tuesday!" the class said together.
"And who visits us on Tuesdays?" she asked.
"Professor P!" the class replied happily.
"Hello, children!"
It was Professor P! The children in Mrs. Webber's class knew him by his thick glasses and white beard that ran to the floor. He was always smiling and ready to teach them something new about math.
"What will we be learning today, Professor P?" asked one of the children.
"I've brought in a truly magical machine, children," said Professor P.
"What does it do?" asked one of the children.
Professor P. could hardly contain his excitement! "Why, this machine can do anything to numbers that we want! It's one of the most amazing machines in all of the mathematical world! Let me show you!"
"I'll start by putting this box in the machine," said Professor P.
Professor P. pulled a small box out of his pocket. The box was blue with the number 3 written on the side. Professor P. then put the little box through the opening in the top of the machine.
"ERP WACKA CHOO CHOO!" the machine whirred.
Suddenly a small yellow box with the number 6 popped out the bottom!
"Let's try that again!" said Professor P.
Professor P. put the little yellow box with a 6 written on the side and put it in the machine.
"ERP WACKA CHOO CHOO!" the machine whirred again.
Suddenly, an orange box with the number 12 popped out of the bottom.
"I know what it's doing!" shouted one of the children. "It's making a number twice as big!"
"Very good! These machines follow a rule and operate the same way every time you put something in them. Now let's try something a little different, " said Professor P. as he pulled a second machine out from his coat.
Professor P. put the little orange box with the number 12 on the side and put it into the new machine.
"ERP WACKA CHOO CHOO!" the machine whirred again.
Suddenly, a small purple box with the number 8 written on the side popped out!
"If we put this in the machine again, what will happen?" asked Professor P.
"I know!" said one of the children. "It made the number smaller by 4. If we put it in again, it should get smaller again!"
With a smile and a wink, Professor P replied, "There's only one way to find out!" Into the machine went the little purple box!
"ERP WACKA CHOO CHOO!"
Suddenly, a small silver box with the number 4 on the side popped out!
Professor P. smiled widely. "These wonderful machines are called Functions, children! They are a very important part of math, and you'll see them many, many more times in your future!"
"Are there functions big enough to put two boxes into?" asked Mrs. Webber.
"Oh my, yes!" exclaimed Professor P. "There are Functions that need ten things put into them in order to run! But no matter how many things you put into a Function, you only ever get one thing out!"
"I have to go now, children! Don't forget about Functions, as I am sure you will see them again!"
"Thanks, Professor P!" the children said together.
"See you next Tuesday!" said Mrs. Webber.
