var total = 10.90;

totalreal = parseInt(total)
totalrealF = parseFloat(total)
totalrealN = Number(total)

document.write(

'R$ ' + totalreal +  '<br>' +
'R$ ' + totalrealF + '<br>' +
'R$ ' + totalrealN + '<br>' +
'R$ ' + total +          '<br>'

);

R$ 10
R$ 10.9
R$ 10.9
R$ 10.9

R$ 10.90

var total = 10.90;


totalrealF = parseFloat(total).toPrecision(4)


console.log(totalrealF)