```
        /**
         * 加法
         * @param arg1
         * @param arg2
         * @returns {Number}
         */
        function accAdd(arg1, arg2) {
            var r1, r2, m, c;
            try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 }
            try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 }
            c = Math.abs(r1 - r2);
            m = Math.pow(10, Math.max(r1, r2))
            if (c > 0) {
                var cm = Math.pow(10, c);
                if (r1 > r2) {
                    arg1 = Number(arg1.toString().replace(".", ""));
                    arg2 = Number(arg2.toString().replace(".", "")) * cm;
                }
                else {
                    arg1 = Number(arg1.toString().replace(".", "")) * cm;
                    arg2 = Number(arg2.toString().replace(".", ""));
                }
            }
            else {
                arg1 = Number(arg1.toString().replace(".", ""));
                arg2 = Number(arg2.toString().replace(".", ""));
            }
            return (arg1 + arg2) / m
        }
        /**
         * 減法
         * @param arg1
         * @param arg2
         * @returns
         */
        function accSub(arg1,arg2){
            var r1,r2,m,n;
            try{r1=arg1.toString().split(".")[1].length}catch(e){r1=0}
            try{r2=arg2.toString().split(".")[1].length}catch(e){r2=0}
            m=Math.pow(10,Math.max(r1,r2));
            //last modify by deeka
            //動態控制精度長度
            n=(r1>=r2)?r1:r2;
            return ((arg1*m-arg2*m)/m).toFixed(n);
            }
        /**
         * 乘法
         * @param arg1
         * @param arg2
         * @returns {Number}
         */
        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)
        }
        /**
         * 除法
         * @param arg1
         * @param arg2
         * @returns {Number}
         */
        function accDiv(arg1, arg2) {
            var t1 = 0, t2 = 0, r1, r2;
            try { t1 = arg1.toString().split(".")[1].length } catch (e) { }
            try { t2 = arg2.toString().split(".")[1].length } catch (e) { }
            with (Math) {
                r1 = Number(arg1.toString().replace(".", ""))
                r2 = Number(arg2.toString().replace(".", ""))
                return (r1 / r2) * pow(10, t2 - t1);
            }
        }
        ```
 

呼叫示例
alert(accMul(7.88,0.8));//乘法
alert(accDiv(7.88,0.8).toFixed(2));//除法
alert(accAdd(7.88,0.8));//加法
alert(accSub(7.88,0.8));//減法