But 0.1 * 10.0 does equal 1.0 if your arithmetic unit is working properly. And actually your argument about the "the slight additional costs to do Decimal Floating Point is small enough that if we were to start over, it could be argued that it would make more sense to use decimal floating-point rather than binary" is completely bonkers. The fact of the matter is that in the "olden days" when "dinosaurs roamed the earth" and the computing power that you now have in your wrist-watch filled rooms the size of football stadiums, arithmetic and floating-point calculations were indeed performed in Decimal. However, they no longer are done that way and the CISC instructions that used to exist in CPUs to do that sort of arithmetic have long since been retired. The reason? It was proven that there was no point, that it was terribly inefficient, that it had extremely high cost for no discernible advantage, and that it was inherently more error prone and had a wider error margin than using base-2 floating-point. It is sort of like once upon a time there were people that believed the Earth was flat (apparently there still are) even though we learned better. Once upon a time people believed that the Sun and stars rotated around the Earth. Then they believed that the Earth and stars rotated around the Sun. But now we have a more complete understanding that everything is moving away from and rotating around a single point of origin. For the moment. Who knows what we will "discover" tomorrow. What you are saying is that perhaps we should revert to the belief that the Earth is Flat simply because computing euclidean geometry is "easier" than computing spherical geometry, despite its known problems and inaccuracies when dealing with real-world problems. This is to deny advances in knowledge simply because you do not like them and are prejudiced in your belief system. This is basically the same sort of behaviour as confronted Galileo.