From the early stages of student life we realized that mathematics uses various symbols to represent sentences, operations, expressions and much more. Using symbols to replace whole sentences is part of recent mathematics, from around the 17th century onwards. You might be asking yourself, "Recent part of math?" Recent if compared to some mathematical works dating back to before Christ. Prior to this period, the use of symbols was very limited or almost non-existent. Every mathematical situation was described using only words.
Surely you know several symbols to represent some mathematical expression. But do you know the use of the exclamation point in math?
In math, the exclamation mark (!) means factorial. Factorial is a mathematical operation that uses multiplications. See some examples:
4! = 4 x 3 x 2 x 1 = 24
6! = 6 x 5 x 4 x 3 x 2 x 1 = 720
9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 = 9!
Knowing that 9! = 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 = 362 880, have you ever thought how to write 362 880! ?
One way could be this:
362 880! = 362 880 x 362 879 x 362 878 x 362 877 x 362 876 x... x 3 x 2 x 1
Using this method, we would spend a long time writing these multiplications. Using factorial, this would be simpler. Check it out:
362 880! = (9!)!
We only used three symbols to write that huge multiplication. In this way, we can verify the importance of symbols in mathematics. Expressions, equations, sentences, everything becomes simpler with the use of symbols. Now you know one more symbol, increasing your arsenal of features to simplify writing in the math language.
By Marcelo Rigonatto
Graduated in Mathematics
