JS para el número de bucle más
var nums = ['100','300','400','60','40'],
sum = nums.reduce(function(accum, val) {return accum + Number(val);}, 0);
alert(sum);
Borma
var nums = ['100','300','400','60','40'],
sum = nums.reduce(function(accum, val) {return accum + Number(val);}, 0);
alert(sum);