This is basically the unwritten rulebook of data quality that every scientist silently weeps about. When you add or multiply two precise measurements, you lose a tiny bit of precision—it's like trying to maintain a perfect GPA after one C+. But the real tragedy strikes when any calculation involves garbage data. No matter how pristine your other measurements are, one piece of trash input transforms everything into trash output. The mathematical horror escalates: square your garbage? Congrats, it's worse garbage! Try averaging multiple garbage values? Still garbage, just wearing a fancy statistical hat. And that last rule about garbage multiplied by zero equaling a precise number? That's the cruel joke of mathematics—the one time garbage disappears is when you multiply by the one number that erases everything anyway! This is why scientists are so obsessive about measurement precision. One sloppy reading and suddenly your Nobel Prize-worthy research becomes suitable only for the mathematical dumpster.