JSFiddle - React, Tailwind, and code Playground

HTML

<button onclick="createInline()">
  Inline
</button>

<button onclick="createPrototype()">
  Prototype
</button>

JavaScript

class MethodsOnPrototype {
	constructor(x, y){
  	this.x = x;
    this.y = y;
  }
  xPlusY(){
  	return this.x + this.y;
  }
  xTimesY(){
  	return this.x * this.y;
  }
  xMinusY(){
  	return this.x - this.y;
  }
  xDividedY(){
  	return this.x / this.y;
  }
  yPlusX(){
  	return this.y + this.x;
  }
  yTimesX(){
  	return this.y * this.x;
  }
  yMinusX(){
  	return this.y - this.x;
  }
  yDividedX(){
  	return this.y / this.x;
  }  
}

class MethodsInline {
	constructor(x, y){
  	this.x = x;
    this.y = y;

  	this.xPlusY = () => {
      return this.x + this.y;
    }
    this.xTimesY = () => {
      return this.x * this.y;
    }
    this.xMinusY = () => {
      return this.x - this.y;
    }
    this.xDividedY = () => {
      return this.x / this.y;
    }
    this.yPlusX = () => {
      return this.y + this.x;
    }
    this.yTimesX = () => {
      return this.y * this.x;
    }
    this.yMinusX = () => {
      return this.y - this.x;
    }
    this.yDividedX = () => {
      return this.y / this.x;
    }  
	}
}

window.createPrototype = function(){
	createThem(MethodsOnPrototype)
}

window.createInline = function(){
	createThem(MethodsInline)
}

window.allInstances = [];
function createThem(T){
	for (let i = 1; i <= 250; i++){
  	for (let j = 1; j <= 2; j++){
    	allInstances.push(new T(i, j));
    }
  }
  console.log(allInstances.length, 'created')
}