When I first started trading resources and food, I was confused as to how it worked. The problem was that when you click to trade, there are two arrows (left to right and right to left). This normally indicates that something can be traded for back and forth. Please replace with a single direction arrow.
I understand that the resource they have to trade is listed on the geoscape map, but when I was first starting I didn’t know if they wanted that resource or had it to trade. Only by means of deduction did I figure it out. I still sometimes forget when I am in the information page which resource they are wanting to trade for.