Theory:

Have you ever visit a library?
 
If yes, you might have seen that the books are arranged in the subject genre-wise. If we need any history book, we can find that it is a history section. We cannot find economics books in the arts section. We are using this method to identify and collect a book quickly.

Similarly, the data also maintained and represented in a particular manner to give a better and easy understanding to the user.

One of the many representation ways is called a tally mark.

The tally mark gives a precise understanding of the data figures. Let's see an example to understand this concept.

The teacher collected the below data from \(20\) students of their favourite sports. The teacher used a tick mark  to represent a number of students.
 
Favourite sports
The number of students liked
Frequency
Cricket
      
\(10\)
Football
  
\(6\)
Volleyball
\(2\)
Basketball
\(2\)
 
Though the tick mark was easy to represent, we could not count each and every tick mark, which is tedious and time taken. For example, if \(10\) tick mark is plotted, we have to count ten tick marks individually, then only we can confirm it.

But in the tally mark method wherein a first sight, we can say the count of the data.
 
Favourite sports
The number of students liked
Frequency
Cricket
IIIIIIII
\(10\)
Football
IIIII
\(6\)
Volleyball
II
\(2\)
Basketball
II
\(2\)
 
The speciality of the tally mark is once it reaches the \(4\) it strikes out and becomes as \(5\), so whenever the tally mark is a strikeout, we should read it as \(5\). This precise elaboration gives the best representation of the data.