Setting a value seems to be the basic procedure of a rational man in his pursuit of dealing with reality, at least since the modern times.
But usually we can only gather, store or try to predict values that the world/nature/fate/deity applied to the phenomena around us. What will be the harvest, how many will be taken away by epidemic etc.. All these are the numbers we want to know and try to affect.
This device, despite being seemingly useless, is the ultimate tool. You can use two buttons to set just any value you want within 0 - 9999.
Moreover, the brave ones can go beyond the scope of the thinking. Once mathematicians were not able to deal with the negative numbers and going below 0 could possibly be something hardly imaginable or even mysterious. Even though we're not scared by -10 nowadays, the limit is still there and has been pushed not too far.