I'm having a small doubt in shell Scripting

I have a program (a.out) which I run several times and it prints a particular value on to the terminal. I need to write a shell script to capture the output of this program and add the outputs.

I wrote the following script

```
value=0
total=0
for((i=0;i<10;j++)) 
do   
 value=`./a.out $i`
 total=`expr $total + $value`
done
echo value is $value total is $total

```

Here, I run a.out with an argument being the i values. When I run this script, I get the error `expr: non-integer argument`

The problem here is with value variable. My a.out gives a double as an output and I need to capture this number in a variable.

I'm a newbie in shell scripting, Can some one please help me on this.