How much is pay to the bearer on demand 10 dollar bill worth?

A "pay to the bearer on demand" $10 bill is worth its face value of $10. This means that anyone presenting the bill can redeem it for $10 in legal tender. The value remains unchanged unless it is damaged or if there are specific collector's interests that might increase its worth. In general circulation, however, it holds the same value as any other $10 bill.