there is a bug in the explore. I was exploring and the acreage i could explore per turn kept going and UP nand DOWN until i decided that i had to stop exploring.

The acres per turn that you can explore is an approximation. Over the amount of turns you explore at that acreage, it will be near the average of the amount it says you can get per turn.

what sigma says.

it's not really that "exact" acreage you get as EPT every explored turns but nearest (above or below) that line.

For each turn spent, you can claim about X acres of land.

The keyword here is 'about'