Dealing with floating point precision in power function

class Core{
    to_fraction(decimal, tolerance = 0){
        var skipped = false; 
        if (isNaN(decimal) || isNaN(tolerance)) return; 
        for (var denominator = 1; (decimal * denominator) % 1 != 0; denominator++) if (Math.abs(Math.round(decimal * denominator) / denominator - decimal) < tolerance){skipped = true; break}; 
        if (skipped) return {numerator: Math.round(decimal * denominator), denominator: denominator, difference: Math.round(decimal * denominator) / denominator - decimal};
        if (!skipped) return {numerator: decimal * denominator, denominator: denominator};
    }

    dplaces(a){
        if (a.toString().split(".").length == 1) return 0; 
        return a.toString().split(".")[1].length; 
    }
}


class Correct{
    cf(a, b){
        return Math.pow(10, Math.max(core.dplaces(a), core.dplaces(b))); 
    }

    divide(a, b){
        var _cf = this.cf(a, b); 
        return (a * _cf) / (b * _cf); 
    }

    multiply(a, b){
        var _cf = this.cf(a, b); 
        return (a * _cf) * (b * _cf) / (_cf * _cf); 
    }

    subtract(a, b){
        var _cf = this.cf(a, b); 
        return ((a * _cf) - (b * _cf)) / _cf; 
    }

    add(a, b){
        var _cf = this.cf(a, b); 
        return ((a * _cf) + (b * _cf)) / _cf; 
    }

    pow(a, b){
        var fraction = core.to_fraction(b); 
        
        for (var count = 0, result = 1; count < fraction.numerator; count++) result = this.multiply(result, a); 
        
        result = result ** (1 / fraction.denominator); // Da problems starts here

        return result; 
    }

    factorial(number){
        if (number % 1 || !(Math.abs(number) >= 0)) return NaN; 
        if (number > 170) return Infinity;
        var result = 1;
        while (number > 1) result *= number--;
        return result;
    }
}

const core = new Core(), correct = new Correct(); 

console.log(correct.pow(7.154840569262962e+21, 1 / 5));