javascript小数精度丢失的完美解决方法

function aDiv(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 aMul((r1/r2),pow(10,t2-t1));  
 }  
 }  / 何问起 hovertree. /
 //乘法 
 function aMul(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)  
 }  
//加法  
function aAdd(arg1,arg2){  
var r1,r2,m;  
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))  
return (arg1m+arg2m)/m  
}  
//减法  
function Subtr(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)); 
  n=(r1>=r2)?r1:r2; 
  return ((arg1m-arg2m)/m).toFixed(n); 
}