Wooden form board with various shapes, marked 37006 and pencilled 'No. 6', by C.H. Stoelting Co. Chicago

Test No. 37006 is an intelligence test. It consists of wooden blocks and recessed niches. The blocks are cut at an angle of 45 degrees. This makes them difficult to match and requires more sophisticated application by the subject. The test cost $11.75 when it was sold in 1930 via American manufacturer C. H. Stoelting and Company. It sold intelligence tests of varying difficulty. The complete set cost $58.50. The company specialised in aptitude testing equipment. These included books, puzzles and mechanical apparatus. The tests used shapes, not language. It made them appropriate for people with limited English skills such as children or immigrants.