replace blank with 0.00 for decimal number

i tried to replace blank value of column which is of type decimal number  to 0.00 .

I create new column 

if(ISBLANK([column1]),0.00,[column1]) ...but am getting 0 instead of 0.00.

If i put 0.02 in custom column...it is correcting getting values as 0.02.

plse help...