it also helps to visualize what the scale really means. 1 to 18 means one real life measurement to 18 "toy" measurements, in our case, inches or feet. So, an object that is 2 inches long, like a toy macheter would be 36 toy inches long, roughly 3 feet. A 4 inch tall figure would be 72 toy inches tall, or about 6 feet. (1/18 = 4/72)
1/6 scale is a little easier on the number cruncher. A foot tall gi joe man is about 6 toy feet tall.
so, those little toy battleships are in 1/72 scale or 1/240 or whatever, so you have one real inch equaling 72 inches or 240 inches, so the bigger the second number, the smaller the model, because you are shrinking it down more.
a true to life size statue is 1 to 1 scale, because the "real" and the "toy" measurements are the same.
I dont know if that helps you or not, but it certainly confused the crap out of me.
Now, this is not to say I bust out a ruler and a notebook everytime I take a picture. You gotta get down there and eyeball it to see if it looks right.