3 ms·On the HP it's 5 ENTER 4 +by dhimes 6y agoOn the HP it's 5 ENTER 4 +kps 6y agoOn the Sinclair it is in fact 5 + 4 + because there is no ENTER key — the first ‘+’ is adding 5 to 0.dhimes 6y agoOdd. So you have to clear first, usually?kps 6y agoApparently so. I don't have one, but see Ken Shirriff's emulator http://files.righto.com/calculator/sinclair_scientific_simulator.html http://files.righto.com/calculator/sinclair_scientific_simul...