Wooden blocks measuring 5.5 x 2.75 x 1.375 inches. This is the basic unit with its 4:2:1 ratio upon which all other shapes are based. Educator Caroline Pratt extended Froebel's Fourth Gift using a slightly larger wooden block made from hard maple.
Wooden blocks measuring 2.75 x 2.75 x 1.375 inches. These square blocks are half the length of the basic standard unit block but the same width and depth. In cheaper sets, half units may be substituted for standard unit, or even called standard units, to increase the advertised block count and reduce shipping weight. Compare with Melissa & Doug 60 Standard Unit Blocks.
Wooden blocks measuring 11 x 2.75 x 1.375 inches. These blocks are twice as long as the standard unit block. In cheaper sets, there may be only two or less of these to increase the block count and reduce shipping weight.
Wooden blocks measuring 22 x 2.75 x 1.375 inches. These blcoks are four times as long as standard units. Almost nonexistent in economy unit block sets. Compare with Melissa & Doug 60 Standard Unit Blocks.
Wooden blocks measuring 5.5 x 2.75 x 1.375 inches. The same dimensions as the standard unit except for a 1.375 inch radius quarter circle and half pillar removed from the one 5.5 inch edge creating an "L" shaped block. Two of these may be use together to create a Roman Arch.
Wooden blocks measuring 11 x 8.25 x 1.375 inches. These blocks add a half unit to one end of a 8.25 inch radius quarter cicle arch. A standard unit can fit under the half unit and a 2.75 inch radius quarter circle and 5.5 inch radius quarter circle arch can fit under the curved portion of an elliptical curve.