For the prompt: the richer get richer, the poorer get poorer. Made me think of money so here you go!
"It's Tuesday, my sons."
Two of the three green boys whined. The fourth one pretended to be in a coma.
"Your minds are at their sharpest on Tuesday mornings. We will take advantage of that opportunity," Splinter instructed and then promptly darkened his eyes when a loud snore filled the tiny room. The teacher used the worn textbook and viciously swiped at his comatose son. "Michelangelo! Nothing will keep you from this lesson. No illness, coma, or death. Wake up this instant!"
Up shot the five year old, lip quivering and curling his stumpy body on the mat. His brothers snickered at his predicament. Young Donatello waved his hand in front of the other pupils, impatient to start the lesson and a testy Raphael slapped the hand out of view.
Splinter continued the Lesson of the day: counting money, and he tried to make it fun for his students. Mikey was intelligent, Splinter knew, but the lad wasn't interested in math; he fussed and caused trouble for his siblings. Begrudgingly, Splinter put Mikey in the dojo and exercised another math lesson: counting flips.
Raphael was scheming a similar plan, but Splinter caught the wild look in the boy's eyes and destroyed any further thought of it with a tap of the cane to his plastron. The lesson continued for another hour.
"Donatello and Leonardo, I am impressed with your attention to detail today. Please enjoy free time for an hour." Splinter's smile was enough for his sons, and they happily took off to their destinations. Raphael's lip slightly trembled, and Splinter almost thought it was cute until those chubby arms crossed and green shoulders hunched. "Raphael, you and Michelangelo need extra tutoring. You remember today's lesson, my son. Here."
Splinter's furry hands gently took Raph's palm and dropped a few coins into it. "Use today's lesson and teach your brother in the dojo. There will be a short quiz in thirty minutes. Be off."
The student groaned but left the classroom and entered the dojo in a better spirit knowing that he was playing the teacher now.
"Count this!" Raph threw some of the coins at Mikey in mid air. "We have a quiz in a little bit."
Mikey retrieved the coins and stood in front of his brother. "What do I need to do?"
"What's more? Ten pennies or a dime?" A teasing smile crawled across Raph's face as he watched his brother poke at the coins in his green hand. "If you don't act like a dumdum, we can go watch 'Interstellar Muscle Cows of Supernatural Factory'."
Mikey's face lit up and then twitched at the coins. "Um, um. Ten pennies!"
"Dummy!" A hand bapped Mikey's head.
"There are more pennies!" Mikey whined. Raph growled and held up the dime, shaking it in Mikey's vision.
"They're the same, banana brains! Ten pennies equals one dime!" He snatched the coins from Mikey's hand. "You can remember history dates but you can't remember something like this?"
"Math makes me feel sick to my stomach," little Mikey whimpered.
Raph huffed and pointed to the dojo's walls. "Doing a million flips made ya sick, stupid! Splinter's coming so you better answer right or no Muscle Cows!"
"I bet those guys never ever have to do math!"
Mikey quickly reviewed his lesson. Parental unit was coming around the corner.