C# If(textbox.text=number) error

I making a quiz in which users would have to enter a number (e.g. 4) into a textbox then the program would check if the number entered is correct. Unfortunately, I'm having some trouble with this part of the code.

So currently I have this code, "if(textbox1.Text=4)" but the four is underlined with the error message, "cannot implicitly convert type 'int' to 'string'".

Can I trouble you all to help me find out what's wrong with my code? Thank you so much!!