Am interesting question you may ask. Of Course! I hear you say. I could never do algebra and logarithms, couldn't see the point in it, but I could add, subtract, multiply and divide, especially if it was about money! With my recent obsession with deciphering blood test results, I have realised that they are misleading!!??** Take for instance my Vit B 12 reading - it reads 203 in a range of 120 - 625. So you look at 203 and think so that about a third in the range. BUT NO. The range starts at 120 - subtract 120 from 625 and you have 505 - that is 505 "points" in the range. You with me? My reading is 203 - subtract 120 from 203 and you have 83. So I have 83 points in a range of 505 points which means that you (I) have less than one FIFTH of the range!! But on first glance it doesn't appear like that it seems more. I'll let you have a think about this before I do another example! Love to ALLx