How to compare quantities and values?

For quantities, you really need to compare them from a more relative view. I think it is incorrect to say "x is close to y" and "z is far from y". You need a point of reference when discussing distance, so saying "x is closer to y than z" is correct. Of course, you can define what it is to be "close". If you say "x is close to y if |x - y| < epsilon" for some epsilon, then it could work out, but otherwise it is meaningless.