Tally marks, also called
hash marks, are a
unary numeral system. They are a form of
numeral used for
counting. They are most useful in
counting or tallying ongoing results, such as the
score in a game or sport, as no intermediate results need to be erased or discarded. However, because of the length of large numbers, tallies are not commonly used for static text. Notched sticks, known as
tally sticks, were also historically used for this purpose.