Okay kiddo, have you ever played store or restaurant with your friends or family? Well, imagine that the whole country is like a big store or restaurant, and the money that people give to the government is like the money that you give to the cashier at the store or the server at the restaurant.
The Baron of the Exchequer is kind of like the boss who's in charge of making sure all the money that people give to the government is counted and put in the right place. They also make sure that the government has enough money to pay for all the things it needs to do, like build roads and hospitals, pay policemen and firemen, and give money to schools and libraries.
The Baron of the Exchequer works closely with other people who help him keep track of the money, like accountants and bankers. They use computers and other tools to make sure everything is accurate and up-to-date. The Baron of the Exchequer is a very important person because he helps make sure that the government has enough money to take care of all the people in the country.