I created this formula which magnificently rounds a number UP to the nearest "log multiple" of 1, 1.5, 2, 2.5 or 5:
=CEILING(B4,10^INT(LOG(4*B4))/2)
Now I would like to modify this so that it rounds a number DOWN to the nearest "log multiple" of 1, 1.5, 2, 2.5 and 5, so I tried the following...