When people fill ice-cube trays, they often put little more than a little puddle in each plastic cup. The reason is that they have heard that water, unlike most materials, expands when frozen. I hate to be anticlimactic, but the amount of expansion in volume is about 10%. Two cubes that differ in this volume are impossible to distinguish unless placed side by side, because the linear dimensions of the big one are only 3% larger. However, in a cup of an ice-cube tray, because the sides are almost vertical, except at the bottom and top, the height will in fact increase by about 10%. This still isn't very much, especially considering that there is a bit of space at the top for it to expand sideways into.
But as I was watching my daughter refilling an ice-cube tray the other day, moistening the bottom of each cup, it occurred to me that what people visualize, if they haven't done the math, is ice exploding out of control, sort of like the Incredible Hulk. From each little plastic cup in the tray, an iceberg will emerge capable of sinking the freezer as though it were the Titanic. "More," I said to my daughter. She splashed a bit more water in. "More," I said, wrestling it from her and proceeding to fill each cup almost to the rim.
Poor child; she grew up in a house with an automatic ice maker, and is ill-equipped for the real world. But it's a parent's duty to train each child to deal with the myriad threats the world poses, and I do not shrink from my duty. There are many things I cannot shelter her from out there, but one of them is a tray full of those dinky ice cubes of every size except "large."