Geomantic omen of wall block

Square building blocks: although the spliced building blocks are concave and convex, the volume of concave-convex joints has not changed after splicing, and it can be considered that the building blocks are several closely combined cubes. Each volume is 6 times 6 times 62 16 cubic centimeter.

The wall 300 times 600 times 180 is 32.4 million cubic centimeters.

* * * Need 66,000 yuan, junior high school topic. Clever calculation.

Regular hexagonal prism building blocks: the distance from one side to the other is three centimeters, with six roots, and the distance from one corner to the diagonal is twelve centimeters. The thickness of the wall is 600 cm, which is the length of 50 bricks. The length is 300 cm, which is the length of 87 bricks, and the height 180 cm is the height of 30 bricks. Therefore, 50 times 87 times 30 equals 13050, which requires bricks and some filling materials.

Regular prism building blocks, six times that of hexagonal prism building blocks, 78,300 pieces.

I don't understand why such a small building block is used.