Robertson County Oil and Gas Lease confusion

An energy company representing XTO is trying to negotiate with me for gas and oil mineral rights to several tracts of land in Robertson County. He talks about money per TRACT rather than money per acre. Some of these tracts are over 50 acres. Should he be talking to me about a price per acre rather than a price per tract? By the way, the numbers he is suggesting are really low compared to what I've read being offered per acre on this site. Any advice would be appreciated.

Divide the number of acres in that tract, into the total sum of money offered ............ what are they offering per acre?