Pecoflyer:
thanks, but i already looked at the excel help file & no, it's not "all there" - it doesn't answer either of my questions, that's why i posted my request

Kimberly:
i know that 0.5 is half of 1......but i'm not sure how that actually answers my question - 50% of what?

this is an example from a book i'm using to get the basics of excel, but the explanation is not very clear so, after experimenting with the formula & looking at both the excel help file & googling i thought i'd ask here.

to experiment i created a column of numbers (1 - 100) & used the formula. i couldn't see what the <0.5 was doing......the < is an operator, so what's it operating on, what's it actually comparing to 0.5 to to see if it's less than it or not?

the results i got didn't seem to relate to the numbers in the column & then i discovered that i get a series of yes's & no's even if i use the formula in a new & otherwise fresh workbook. so, & sorry if i'm labouring the point here, but what is being compared to 0.5 to decide whether to return "yes" or "no"?

Thanks