It was a sunny day at Ponyville. Everypony was busy today including the purple librarian and Princess pony who lived in the Golden Oak Library, Twilight Sparkle.
Twilight was pacing around the room with her checklist in front of her. The list in question was the things she needed for tonight’s sleepover with the girls including Spike because she felt that Spike should also have some fun too after working so hard for her lately.
Earlier, Twilight asked her friends to gather all the things they needed for the sleepover to add more fun or something to snack on. Her friends wholeheartedly obliged and they each brought over their own stuff to contribute to tonight’s sleepover. While everypony else was still getting ready, Twilight looked over everything on the list what seemed like a hundredth times.
“Let’s see, sleeping bags, check! Pillows, check! Board games, check! Drinks, check! Large fruit salad for dinner, check! Cookies for dessert…”
As Twilight looked over the line that said, Cookies for Desserts by Pinkie Pie, she noticed that there is no check mark next to it yet.
“Huh, I thought Pinkie Pie said she’ll have the cookies ready by-”
“Hey Twilight~!” Pinkie Pie shouted who suddenly appeared out of nowhere.
“AH!” Twilight yelped.
Twilight nearly jumped towards the ceiling by surprise. She quickly recovered her surprised state and then had a look of annoyance on her face once she realized it was Pinkie.
“Pinkie, where did you come from?” Asked Twilight while her heart was still pounding.
“Through the front door.” Pinkie replied as if the answer was obvious.
Twilight facehoofed. “Pinkie, what did I tell you about not sneaking up on me like that!”
Pinkie giggled, “Sorry Twilight, but lookie here, the cookies are all done!”
Twilight’s annoyed look disappeared when she saw a bag of cookies sitting on Pinkie’s back. The smell of freshly baked cookies nearly hypnotized her and almost made her drool.
“Excellent Pinkie!” Praised Twilight. “Now that you brought over the cookies, the things we need for our sleepover is finally done!”
“Glad I can help Twilight!” Pinkie said with a smile.
As Twilight used her magic to lift the bag of cookies off of Pinkie’s back, Twilight asked, “So how many cookies did you bake Pinkie?”
“I baked exactly twenty-eight cookies!” Pinkie responded with a smile.
Twilight placed the bag of cookies down on the table and then faced Pinkie with her one eyebrow raised. “Twenty-eight cookies? Why twenty-eight?” asked Twilight.
Pinkie giggled, “Well, it was originally thirty cookies I baked earlier, but Pound and Pumpkin really really wanted to taste my cookies so I gave them one of each. Don’t worry, the cookies were soft! It was so cute the way they nibbled~.”
Twilight nodded with understanding.
“Even so, do we have enough cookies for everypony to go around?” asked Twilight. “I’m sure everypony including Rainbow, Applejack and Spike will fight over the amount of cookies.”
“Chill out Twilight,” Pinkie reassured as she waved her hoof. “I got this whole thing figured out! After I baked the cookies, I calculated the amount of cookies for us to have evenly.”
“You did?” Twilight asked, impressed that Pinkie already planned it in advance.
Pinkie nodded, “Yepperoni! Since I baked the total of twenty-eight cookies and there’s only seven of us including Spike, we should each have thirteen cookies!”
“Yes that sounds about- wait, what?”
Twilight blinked and then titled her head on the side with a confused look on her face.
“Did… did you say, we each get thirteen cookies?” asked Twilight, not sure if she heard Pinkie right.
Pinkie nodded with a smile, “Sure did!”
“Thirteen?”
“Yep, that’s what I said!”
As Twilight stared at Pinkie with a stunned look on her face, she did her own calculations in her head. Even after she figured out her own math, Pinkie’s answer still didn’t make any sense to her.
Twilight shook her head, “Pinkie… seven times thirteen isn’t twenty-eight.”
“Yes it is!” Pinkie insisted.
“No it’s not!”
“Sure is!”
“Pinkie, seven times four is twenty-eight, not thirteen!”
“Nah, I’m pretty sure that seven times thirteen is twenty-eight.”
Twilight squinted her eyes at Pinkie, “Pinkie, do you ever go to school?”
“Sure did!” said Pinkie. “I even have my degree with me, see?”
With her tail, she pulled out her degree from her mane, which was covered with small patches of frosting stains and pink hair. The degree itself is actually a Bachelor of Science in Psychology from Rockvile University with a legit seal and a signature, assuming from the Dean. Twilight was not sure what to make of this. Twilight wanted to ask Pinkie why does Pinkie felt the need to get a B.S. degree for partying and baking, but Twilight decided to put that aside and focused on the main issue.
“Pinkie… I read many mathematics books from basic to advance level and I can assure you that seven times thirteen is definitely not twenty-eight!”
Pinkie stuffed her degree back in her mane and then giggled, “Silly Twilight, you got to keep yourself updated. Your books are totally outdated when it comes to math!”
“They are not outdated!” Twilight snapped. “These books are current! These copies of books came from Celestia's School for Gifted Unicorns!”
Pinkie gasped, “Well no wonder, the school itself is probably fallen behind with mathematics!”
Pinkie gently draped her hoof around Twilight’s neck and gave her a sympathetic look. “I am so super-duper sorry for you Twilight, especially that you enrolled in a school that couldn’t keep up with the times.”
Twilight let out her frustrated groan. She was about to argue with Pinkie but she stopped herself. Remembering her sister-in-law’s advice, Twilight calmed herself down by placing her hoof to her chest, and then breathed out, as she extended her hoof. Once she calmed herself, Twilight was thinking of a way to show Pinkie just how absurd her math was.
Then she had an idea.
Twilight turned towards Pinkie, “Alright Pinkie Pie, if you’re so sure of this, then I want you to prove it!”
Twilight lit up her horn from her magic and then a large chalkboard on wheels appeared right in front of them.
Twilight pointed at the chalkboard with her hoof. “If you can prove it to me that seven times thirteen is in fact twenty-eight, which is not, then I’ll be your official assistant baker for the entire week!”
“REALLY?” asked Pinkie while her eyes sparkled with glee. “You’ll be my official assistant baker for the week?”
Twilight nodded, “Really.”
Normally, Twilight never liked to bake or cook for that matter. She let Spike do all the cooking for the both of them. She tried to cook a few times before, but… let’s just say her food came out worse than Sweetie Belle’s burned toast.
Pinkie was ecstatic that her best friend is going to be her assistant baker for the week. She offered to teach Twilight how to bake so many times before, but Twilight always turned her down. Now that Twilight is going to be her assistant baker, Pinkie came up with so many possibilities of what she and Twilight can do together at the Sugar Cube Corner.
Pinkie was about to leap into the air and start to celebrate, but Twilight interrupted her. “However, if you can’t prove it, then you’ll have to give me a free milkshake from Sugar Cube Corner every single day for the entire week! Do we have a deal?”
Pinkie Pie had a serious look on her face with her hoof on her chin as she was thinking about Twilight’s deal. After a short moment, Pinkie Pie nodded.
“Okay Twilight, its a deal… but you’ll have to Pinkie Promise me that you’ll honor your deal!”
“Fine,” Twilight said, “but only if you Pinkie Promise as well!”
They both nodded and performed their Pinkie Promise chant.
“Cross my heart and hope to fly, stick a cupcake in my eye!”
Pinkie nodded with her satisfied smile, “Great, so it’s official! Just don’t get too upset after I prove it to you.”
“IF you can prove it!” said Twilight feeling confident.
Pinkie giggled, “Of course I can silly, I’ll show you.”
“Then show me!” Twilight challenged as she levitated a piece of chalk to Pinkie with her magic.
“Okey-dokey-lokey!” Pinkie chirped.
Pinkie took the chalk from Twilight with her hoof… somehow, and then turned towards the chalkboard.
“Okay, so there’s only seven of us at the sleepover right?” asked Pinkie.
Twilight nodded, “That’s correct.”
“Alrighty, I’ll put in a seven.”
With her chalk, Pinkie wrote down a huge number seven on the chalkboard.
Pinkie turned to face Twilight. “We have the total of twenty-eight cookies I baked for the sleepover, right?”
“That’s right.”
“Okay, then I’m going to divide.”
Pinkie turned towards the chalkboard again and wrote down the number twenty-eight in between the brackets right next to the number seven on the right.
7)28(
Pinkie turned to Twilight again. “Okay so here’s twenty-eight trays of cookies.”
Twilight studied the writings on the chalkboard for a moment and then shifted her eyes at Pinkie.
“Now you claimed that seven goes into twenty-eight thirteen times?” Twilight questioned.
Pinkie nodded, “That’s right!”
“Okay, then show me!” said Twilight.
“Alrighty~!” Replied Pinkie.
Pinkie moved to the chalkboard again while Twilight watched Pinkie’s every move.
“Seven into two?” asked Pinkie.
Twilight shook her head.
“Seven will not go into two!” Pinkie explained.
“Obviously!” muttered Twilight.
Pinkie continued, “No matter how much you push this big ol’ seven into that tiny little two, it won’t budge! I mean why would a big ol’ seven want to push this poor little two around? The little two didn’t do anything to hurt that big ol’ seven! *GASP* What if those two numbers are not friends? That would be super-duper awful! OOH I KNOW! I’ll throw together the ‘Let’s Not Push Each Other Around Anymore and Be Best Friends Instead’ party! Then those two numbers will be best friends for-“
“PINKIE, FOCUS!” Twilight snapped.
Pinkie grinned sheepishly, “Oops, sorry Twilight, I got a little carried away.”
Pinkie eyes went back to the chalkboard again.
“Annnnnyywho, I’m going to take this little two and put it right down there!”
Pinkie wrote a very tiny little two almost towards the bottom of the chalkboard.
7)28(
2
“Look at that tiny little two, isn’t it cute?” gushed Pinkie.
“Oh yes Pinkie, that two is very cute.” Twilight said sarcastically while she rolled her eyes.
Pinkie giggled, “I knew you agree! Now don’t forget that tiny little two~!”
Twilight sighed, “I won’t Pinkie.”
“Good!”
After that setback, Pinkie resumed her math problem to Twilight.
“Now then, seven into eight?” asked Pinkie.
“It’s once!” Twilight answered.
Pinkie nodded, “Right! So we’ll put the one there!”
Pinkie added the number one at the right of the number twenty-eight.
7)28(1
2
“Now I’m going to carry the seven because it’s getting really heavy for me. Soooooo, I’m just gonna put the seven right underneath there!” Pinkie explained.
Pinkie then wrote down the number seven underneath the number eight of the number twenty-eight and then draws a line under the seven.
7)28(1
7
2
“Now, seven from eight?” asked Pinkie.
“It’s one!” Twilight answered again.
Pinkie nodded, “Yep, it’s one! So now I’ll put the one down there!”
Pinkie wrote the number one underneath the seven.
7)28(1
7
1
2
Pinkie turned to Twilight, “Now Twilight, do you still remember that little two I asked you not to forget?”
Twilight sighed, “No Pinkie, I did not forget the two. You told me not to forget the two almost a minute ago!”
Pinkie giggled, “Well I’m glad you didn’t! Because now I’m going to use it!”
Twilight gave Pinkie her skeptical look, “You’re going to use that two?”
Pinkie nodded with her smile, “Yepperoni! So I’m taking the two from here… and place it right there next to the one”
Pinkie erased the tiny two at the bottom of the chalkboard with an eraser. Then she picked up her chalk again and wrote the normal size two next to the number one on its left side at the bottom of the equation.
7)28(1
7
21
Pinkie turned to Twilight again, “Now, seven into twenty-one?”
“It’s three!” Twilight answered.
Pinkie grinned, “Yep, three!”
Pinkie turned towards the chalkboard and wrote the number three next to the number one at the top of the equation, making it thirteen.
7)28(13
7
21
Pinkie turned towards Twilight with her huge grin on her face and pointed at the chalkboard, “See! Seven, twenty-eight, thirteen!”
Twilight’s stood in front of the chalkboard with a look of disbelief. She couldn’t believe that Pinkie can easily make seven into twenty-eight thirteen times even though it is impossible to do! Twilight shook her head furiously as she levitated her eraser with her magic.
“Oh no no no no! This cannot be right!” Twilight shouted as she erased everything on the board.
“Of course it’s right! I just showed you!” said Pinkie.
“Yeah but… this isn’t… I…”
Twilight was about to hyperventilate but she calmed herself down again with her same breathing technique with her hoof from before. Once Twilight finished with her breathing technique, she turned towards Pinkie with her eyes squinted at Pinkie.
“Look Pinkie,” said Twilight. “I’m still not convinced! You got to give me a better proof than that!”
Twilight levitated a piece of chalk with her magic again and presented it to Pinkie. “How about you multiply this time!”
“You want me to multiply it?” asked Pinkie.
Twilight nodded, “Yes, I want you to put down thirteen times seven!”
“Okey-dokey-lokey!” Pinkie chirped.
Pinkie took the chalk from Twilight and wrote down the number thirteen and then the number seven under thirteen with the line drawn under the seven on the chalkboard.
13
7
“Okay Twilight, they’re on the board~!” Pinkie said in her cheerful tone.
Twilight squinted her eyes at the multiplication on the chalkboard and then she nodded.
“Perfect! Now Pinkie, you claimed that seven times thirteen equals to what?” asked Twilight.
“Twenty-eight!” Pinkie said without hesitation.
“Alright, prove it Pinkie!” Twilight challenged.
“You got it!”
Pinkie turned towards the chalkboard again.
“Now, seven times three?” asked Pinkie.
“Twenty-one.” Twilight answered.
Pinkie wrote twenty-one under the line.
13
7
21
“Seven times one?”
“Seven.”
Pinkie wrote seven under the one of twenty-one.
13
7
21
7
“Seven to one?”
“Eight.”
Pinkie drew a line under the number seven and then wrote the number eight under the seven.
13
7
21
7
8
“And two to carry. Twenty-eight!”
Pinkie wrote the number two next to the number eight at the left side, making the two numbers together as twenty-eight.
13
7
21
7
28
“Yep twenty- HEY WAIT A MINUTE!”
Twilight ran up to the chalkboard until her face was close to the board and looked it over for any mistakes.
“THAT’S IMPOSSIBLE!” Twilight screamed.
“It’s possible~!” Pinkie said in her singsong voice.
“NO IT’S NOT!” shouted Twilight as she erased everything on the board with her eraser with her magic again.
“Yes it is~! I just did it!” Pinkie said with a smile.
“UHHHHHG!” Twilight loudly groaned.
All of Twilight’s composure was thrown out the window. Even her sister-in-law’s breathing technique won’t calm her now. Pinkie somehow made the impossible possible again, but with multiplication this time! Twilight was getting desperate, but she had one more idea to make Pinkie realize how ridiculous her math is.
“Alright no horsing around!” Twilight snapped as her left eye twitched.
“But Twilight, we’re ponies not horses.” Pinkie said innocently.
Twilight glared at Pinkie, “That’s not what I… UHG, never mind! I’m still not convinced about this! The only sure way you can prove this is by using addition!”
Pinkie titled her head, “You want me to add?”
“Yes!” Twilight exasperated. “I want you to put down the number thirteen seven times on the board, draw a line underneath them and then add them all up!”
Oblivious to Twilight’s anger, Pinkie nodded with a smile, “Okey-dokey-lokey Twilight! If that’s what you want!”
Pinkie once again picked up the chalk and then wrote down the number thirteen on the board seven times and then drew a line underneath them.
13
13
13
13
13
13
13
“Okay Twilight, all seven thirteens are on the board~!” Pinkie said cheerfully.
Twilight stared at the board for a moment and then looked at Pinkie sternly in her eyes. “Alright, now you claimed that all seven thirteens, adds up to twenty-eight?”
Pinkie nodded rapidly, “Yepperoni! And I’m gonna prove it to you right now!”
Pinkie was about to start adding the numbers but Twilight took her chalk away with her magic.
“Not so fast Pinkie!” Twilight exclaimed. “Let me do all the adding this time!”
Pinkie stared at Twilight with a look of uncertainty, “Are you sure Twilight? I don’t think it’s going to come out right when you do it!”
Twilight gave Pinkie a look that said are you kidding me?
“Pinkie, who do you think you’re talking to?” Twilight said, clearly annoyed. “I was Princess Celestica’s Protégé and was a student from Celestia's School for Gifted Unicorns! I think I’m more than capable to get the correct answer!”
Pinkie still looked unsure but then she shrugged. “Alright Twilight, if you say so!”
“You watch Pinkie, there won’t be a mistake!” Twilight said with high confidence.
Twilight turned to towards the chalkboard and began to count the threes, adding them as she goes.
“Three,
Six,
Nine,
Twelve,
Fifteen,
Eighteen,
Twenty-one!” Twilight cried with her triumphant smile on her face.
Her victorious smile quickly vanished when Pinkie took her chalk and began adding the number ones in the most unusual way.
“Twenty-two,
Twenty-three,
Twenty-four,
Twenty-five,
Twenty-six,
Twenty-seven,
Twenty-eight!” Pinkie said as she wrote down a big number twenty-eight at the bottom of the board.
13
13
13
13
13
13
13
28
When she finished, Pinkie gave Twilight her most innocent smile.
Twilight just stood there in shock while her mouth hung open. Pinkie was able to get twenty-eight by adding thirteen seven times! This boggled her mind! Nothing makes sense to her anymore! Worse of all, she has to be Pinkie’s assistant baker for a week!
Pinkie trotted up to Twilight and patted on Twilight’s back in attempt to cheer her up.
“Hey, cheer up Twilight!” Pinkie Pie said with a smile. “You can still have a free milkshake every day for a week while you’re my new assistant! In fact, you can have all thirteen milkshake favors for free everyday! So that means you’ll get the total of twenty-eight free milkshakes for this week! Great deal, huh?”
Twilight banged her head against the chalkboard repeatedly.
Author's Note
Pinkie got a B.S. degree. Who knew? 
Anyway, I was watching one of Abbott and Costello's videos on YouTube a few weeks back and their 7 x 13 = 28 routine gave me an inspiration for this short story. I couldn't think of a better comedy duo than Pinkie Pie and Twilight! Those two are so funny when they're on screen together, especially when Pinkie unknowingly drove Twilight crazy! 
Anyway, criticism is welcome, but please be nice! 
