Math from Three to Seven by Alexander Zvonkin is a great read and example of this. It recounts experiences running a math circle for preschoolers and really highlights the value of play, curiosity, and open exploration.

From personal experience, and as noted here, this approach is valuable for everyone regardless of age. In the short term it's far more efficient to learn by having the right way 'pushed' to you. However, by taking the time to fail, repeatedly, and eventually 'pulling' that knowledge the tacit understanding you build has a depth that's hard to shortcut.