answer:Well you can think of it in the sense that the longer something you measure is, the less the error is of the whole length. It’s an inverse proportional relationship if you look at the formula. For instance if you use a mm marked ruler and measure something which is 20.0 mm, your uncertainty is then 0.5 mm (from the last defined mark being to millimeters), so you end up with 20.0 +/- 0.5 mm. Then you also measured something thats 30.0 mm you would get 30.0 +/- 0.5 mm. The percentage error is=|measured-actual|/actual length=|error|/actual length So for the 20.0mm=0.5/20.0=0.0250 while for the 30.0mm=0.5/30.0=0.0167