PEMDAS, the Ship's Accountant - A Fairytale.
"You're so smart, and so smart," she'd joke with her son, who also swaggered a bit due to his leg. "The grammaticus is very impressed with your mental acuity. And you have the best suits! One day you'll be accountant for a senator!" Pemdas did not want to be an accountant; he'd kiss his mother on the cheek and squeeze her hand, trying to not look as disconsolate as he felt on the inside.
He went to the docks every Saturday morning and tried to convince the ships' captains that he was a valuable addition to their crew, but none would even look at him, let alone listen.
"I can tell you how many apples you're transporting," he shouted from the dock. Finally a grizzly sailor leaned over and sneered at him.
"Oi, look, Cap'n! 'Ere's that lad wot wants a job!" The captain appeared next to the sailor and stared at Pemdas with a hard eye, while his other eye looked out to sea. Pemdas gave his best pitch.
"Consider that a crate of apples contains 1 bruised apple for every 30 apples in the crate. Additionally, your second crate has been damaged and apples are falling out. So the first crate has 29 apples; the second is 29 discounting a rotten one and 20 apples rolling across the deck..." The sailor laughed, and spit a seed at the boy. "...and deduct the one your first mate just got done eating. 51 apples."
Pemdas was hired immediately to monitor inventory. He was the best-dressed of any accountant on the seas. It's rumored his father Poseidon was proud, because a ship that took Pemdas on its crew never encountered a storm.