Centa the Percent-Translator

From a young age, Centa knew something important. The kingdom's taxes worked with percentages.

The kingdom did not tax things with the same amount for everyone. That wouldn't be fair. A rich trader and a poor farmer would pay the same. That wasn't right. Instead, they taxed things based on how much they were worth. It was a percentage of the cart's value. Grain was taxed at ten percent. Copper was taxed at five percent. Cloth was taxed at two percent. Salt was taxed at twelve percent. Salt was a luxury item. Imported spices were taxed at twenty percent. Spices were a big luxury.

Cent figured out these percentages. He did it for every cart. This went on for fourteen years. Centa watched him her whole childhood.

He figured them out very fast.

A merchant would arrive with a cart. Maybe it held forty bags of grain. Cent would figure out how much the grain was worth. He had a special book for prices. It was made of leather. Then he'd multiply by ten percent. He'd tell the merchant the tax. The merchant would pay. The cart would pass. The next cart would arrive.

By the time Centa was eight, she could figure out ten percent of any number. She did it in her head, super fast. Just move the dot one spot to the left. By the time she was ten, she could figure out one percent of any number. Move it two spots to the left. By the time she was twelve, she could figure out any percentage. She just put the moves together. To figure out twelve percent of three hundred: First, find ten percent. That's thirty. Next, find one percent. That's three. Multiply the one percent by two. That's six. Then add thirty plus six. That's thirty-six.

By age twelve, she was as fast as her father.

Centa realized something big. Percentages were like a secret code. They helped you translate numbers. They were the best way to show a ratio. A ratio is just a way to compare two numbers. Percentages always compared things "per hundred." You could change any ratio into a percentage. Once you did that, you could easily compare them. Three-to-five became sixty percent. One-to-eight became twelve-and-a-half percent. Seventeen-to-twenty became eighty-five percent. The kingdom used "per hundred" for its taxes. It was a common way to measure things. This made comparing any two rates super easy.

She thought about this for years.

When she was twenty, she had been helping her father at the toll-gate. She did this for many years. Then, a traveling scholar passed through Northgate. Centa's father said not to charge him. Scholars didn't pay tolls. The kingdom thought learning was important. The scholar watched Centa all afternoon. He saw her figure out percentages. When the day ended, the scholar came up to Centa. He said:

"You are the fastest percentage-calculator I have met. Have you considered teaching?"

Centa had never thought about it. She thought about it now. She talked to her father. Cent had been a tax-collector for thirty years. He was quiet, but happy. He liked that Centa had other choices. He didn't want her stuck at the toll-gate. He said: "Go. Teach. The kingdom has many tax-collectors. It has few teachers."

Centa went to the RatioRealm academy when she was twenty-one. She studied there for three years. She became a teacher there when she was twenty-four. She has taught percentages ever since.

In her classroom, she starts her first lesson the same way. Every time. She brings a special book. It's a small wooden ledger. Her father made it for her when she was six. It looks just like his big tax books, but tiny. It has small spaces for "cart value" and "tax percent." She places it on the desk. She turns to the class. She says: "What is ten percent of one hundred?"

The children — always — say ten.

Centa says: "What is ten percent of two hundred?"

The children say twenty.

Centa says: "What is ten percent of seventy?"