Percent error question-earth science?

Question

we had to finish a percent error work sheet for homework today. i am kind of confused on it. should i subtract the accepted value before i do the formula? or should i just write out the difference? ex: 10ml-8ml

--------------- X 100

8ml

or

10ml-8ml=2ml

2ml

--------- X 100?

10ml

which one do i do? thanks also i am confused a lot on this one

Which is a larger percent error, 1 cm in a meter, or 1 g in a kilogram? (Please justify your answer by showing the calculations.)

thanks so much!

Answer 1

aren't your two formulas *exactly the same?*

Answer 2

The first one is confusing: I think you have left out some information.

Second one:

1cm in a metre = 1 in 100 = 1%

1g in a kilogram = 1 in 1000 = 0.1%