We all played with building blocks, no? Frank Lloyd Wright credited Froebel Gifts, a type of building block, as being instrumental in his early development "For several years I sat at the little Kindergarten table-top... and played... with the cube, the sphere and the triangle—these smooth wooden maple blocks... All are in my fingers to this day..."
Anyway, here is a study summary that may be of interest.
http://gse.buffalo.edu/org/buildingblocks/writings/Building%...
"Building Blocks is a NSF-funded PreK to grade 2 software-based mathematics curriculum
development project, designed to comprehensively address the most recent mathematics standards. Building
Blocks materials were created upon explicit design principles and a nine-phase formative model—they are
truly research-based (details are provided in Clements, 2002a; Clements, 2002b; Sarama & Clements, in
press)... The materials are designed to help children extend and mathematize their everyday activities, from building blocks to art to songs and stories to puzzles...
...The results are illustrated in two graphs. We computed effect sizes using the accepted benchmarks of
.25 as indicating practical significance (i.e., educationally meaningful), .5 as indicating moderate strength,
and .8 as indicating a large effect (Cohen, 1977). The effect sizes comparing BB children’s posttest to the
control children’s posttest were .85 and 1.44 for number and geometry, respectively, and the effect sizes
comparing BB children’s posttest to their pretest (measuring achievement gains) were 1.71 and 2.12.
Therefore, all effects were positive and large. Achievement gains were comparable to the coveted “2-sigma”
effect of excellent individual tutoring"