1.  Sid Sloppy was not careful in his measurements.  He measured the volume of a 12 oz. bottle to be 14 oz.

(14-12)/ 12 x 100= 17%

2.  Gilbert Goofoff was told to use the balance to find the mass of a 500 g piece of metal.  He goofed off for most of the lab period and then tried to finish his experiment quickly at the end.  Since he was in such a rush he reported the weight of the metal as 458 g.

(458-500)/500 x 100 = 8%

3.  Franny failure was told to measure a length of copper wire 50 cm long to use for her experiment.  She mistakenly measured 45 cm of wire instead, which lead to poor results in her experiment.

(45 – 50)/50 x 100 = 10%