// To force decimal to use only two numbers after coma, you can use this

var numberOne = 4.05;

var numberTwo = 3;

// If you use only this :

var total = numberOne * numberTwo; // This will be 12.149999999999999 (thanks JS...)

// But if you use this : 

var total = Number(numberOne * numberTwo).toFixed(2); // This will be 12.15