How to use Calculator on MacOS Catalina I can't figure how to use Calculator in Catalina. Screenshot is where I keyed in 4 * 3 and an Enter, I get output of 3 instead of 12 and neither can I read what I keyed in nor scroll arrow-up for any previous result.  I thought I had some sort of mental blockage so I actually read the Calculator User Guide for Mac - still didn't find what I did wrong with the Calculator. I regret upgrading to Catalina, everything is just a disaster. I have to use Terminal for basic calculation, if someone can show me how to use Calculator like we used to on the Dashboard or on normal physical calculator...
RPN Mode

The problem most probably stems from the calculator being in the Reverse Polish Notation (RPN) mode. Things should go back to normal if you simply turn the RPN mode off by pressing ⌘+R.