js乘法計算精度

function accMul(arg1, arg2) {  
    var m = 0,
        s1 = arg1.toString(),
        s2 = arg2.toString();  
    try {
        m += s1.split(".")[1].length
    } catch (e) {}  
    try {
        m += s2.split(".")[1].length
    } catch (e) {}  
    return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m)
}