Elementary school student who was curious about the exclamation mark on the calculator.jpg

Among the phone apps, there is a calculator app that allows you to calculate by hand, so my 6th grade brother plays with it.

By chance, the expression ‘3!=6’ popped up, so I asked, ‘What is this “!’?’

Did you figure it out after saying, ‘Calculate ! with several numbers and think of the rules?’ I looked and looked

After a few minutes, ‘Okay, the ! of x is the ! of x-1. An unexpected ignition came out: ‘Multiply x.’