This studied fourth and fifth graders. However I might add my one irrelevant anecdotal data point from when I was in 10th grade 20 years ago. In an attempt to "cheat" at Chemistry class I wrote a stoichiometry equation balancer with step by step answers on a TI-83. I wrote various solvers for Physics class and Stats class. Working through all the edge cases of these problems helped immensely. Fourth and fifth graders just don't have as many opportunities to apply programming to the real world.