cal

// 两个浮点数求和
    function accAdd(num1, num2) {
        var r1, r2, m;
        try {
            r1 = num1.toString().split('.')[1].length;
        } catch (e) {
            r1 = 0;
        }
        try {
            r2 = num2.toString().split(".")[1].length;
        } catch (e) {
            r2 = 0;
        }
        m = Math.pow(10, Math.max(r1, r2));
        // return (num1*m+num2*m)/m;
        return Math.round(num1 * m + num2 * m) / m;
    }

    // 两个浮点数相减
    function accSub(num1, num2) {
        var r1, r2, m;
        try {
            r1 = num1.toString().split('.')[1].length;
        } catch (e) {
            r1 = 0;
        }
        try {
            r2 = num2.toString().split(".")[1].length;
        } catch (e) {
            r2 = 0;
        }
        m = Math.pow(10, Math.max(r1, r2));
        n = (r1 >= r2) ? r1 : r2;
        return (Math.round(num1 * m - num2 * m) / m).toFixed(n);
    }
    // 两数相除
    function accDiv(num1, num2) {
        var t1, t2, r1, r2;
        try {
            t1 = num1.toString().split('.')[1].length;
        } catch (e) {
            t1 = 0;
        }
        try {
            t2 = num2.toString().split(".")[1].length;
        } catch (e) {
            t2 = 0;
        }
        r1 = Number(num1.toString().replace(".", ""));
        r2 = Number(num2.toString().replace(".", ""));
        return (r1 / r2) * Math.pow(10, t2 - t1);
    }
    function accMul(num1, num2) {
        var m = 0, s1 = num1.toString(), s2 = num2.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);
    }