One eighth is .125 in decimal, if that is what you're after, 5.375
One quarter is two eighths, so five eighths subtract two eighths is three eighths.
Two and five eighths
Expressed as a decimal, this is equal to 1.125.
One and a half is twelve eights.plus five eights, is seventeen eights. That is two and one eighth in total, or 2.125 in decimal.
Answer One half is the same as four eighths, so five eighths is one eighth more.