Because the ask price is expressed as "BTC per CRB".  It's the exchange rate you'd be willing to accept.  The ask price isn't the total price for the entire sale.

In your first example, you are selling 1 CRB at a rate of 1 BTC per CRB, which would yield 1 BTC in total (excluding the fee).

In your second example, you are selling 0.1 CRB at a rate of 0.1 BTC per CRB, which would yield 0.01 BTC in total (excluding the fee).

If you wanted to sell 10 CRB for 0.1 BTC per CRB then you would get 1 BTC in total (if anyone was crazy enough to pay that price).

The maths looks correct to me.  Or did i miss something?

Judging by the way you asked the question, I suspect you are looking to sell your 0.1 CRB at a 1:1 ratio with BTC.  In that case the volume would be 0.1, the ask price would be 1 and the total would come in at 0.1 BTC (excluding the fee).  Don't hold your breath waiting for that kind of price to be paid.

By the way, don't just leave your "ask" orders to RIP on the books on that market.  If by some miracle a large chunk of BTC comes in to pay off the debt, they will buy up all the orders themselves (at a fraction of the cost) before making the announcement.