do the more maths from base

inheritedCalculator.js

(function() {

"use strict";

var assign = require("lodash.assign"),
  mathPrototype = {

    total: 0,
    add: function add(number) {

      this.total += number;
      return this;

    },
    subtract: function subtract(number) {

      this.total -= number;
      return this;

    },
    get: function logTotal() {

      return this.total;

  }

  },
  advancedMathPrototype = {

    pow: function pow(number) {

      this.total = Math.pow(this.total, number);
      return this;

    }

  };

advancedMathPrototype = assign(Object.create(mathPrototype), advancedMathPrototype);

function calculate(base, prototype) {

  var functions = Object.create(prototype);

  functions.total = base || 0;

  return functions;

}

var calculator = calculate(0, mathPrototype),
  advancedCalculator = calculate(0, advancedMathPrototype);

calculator.add(5).add(5).subtract(5);
advancedCalculator.add(5).add(5).pow(2);

console.log(calculator.get());
console.log(advancedCalculator.get());

})();