How is acumen used?

Relevant answers:

What is a used in?
In a sentence
Why is a model airplane used and where it is used?
A model aeroplane is used for presentations and testing. Model planes are also used for fun. They are used model-plane clubs, aeroplane company headquarters and studios. (Bedroom, in my house)
Who used Runic symbols and what were they used for?
The ancient Germanic tribes and the ancient Scandinavians used runes as an alphabet. Prior to that, they used runes for magic purposes, such as casting lots (divination) and spells of protection.
Where are robots used and what are they used for?
That people wont work.
Were animals used at Gallipoli and how were they used?
Yes. Horses were used but eventually taken back to Egypt because they weren't of any use at all. Mules and donkeys were originally landed to be used as water-carriers for the troops on the front...