I have the developer tab up and know how to create / insert "Form" and "ActiveX" buttons. I'm just trying to add +1 every time the button is clicked.

i.e.: a1 field is empty....click the button....a1 field now says "1". Click it again....says "2"

I realize this is probably really easy as I used to create really complex stuff in Excel for a job I used to have. It's been 10ish years since I used Excel like this so I'm extreeeeeeeeeeeemly rusty and I'm just staring at my screen. Plz Halp!