EXCEL
I started a new accounting internship and every spreadsheet I have been sent I noticed that a lot of my coworkers will start formulas with +=(etc...) My brother who is also an accountant has told me it is because they are only using the keyboard and not the mouse, so you have to click + then = to start the formula, but that is not true? I can key down to a random cell and click = and the formula will start up. So, my question is why do people using Excel start formulas with "+=" ?