Re: expr --> problem with product functionality

[Alfred M. Szmidt]

   GNU/Linux_box:/ # expr 10 / 2
   5
   GNU/Linux_box:/ # expr 10 * 2
   expr: syntax error

You need to escape the multiplication sign.  Try:

 expr 10 \* 2

And try:

 echo expr 10 * 2

to see why it doesn't work (shell expansion)

Cheers.