Did he try reversing it, doing the sugar-loaded trial first? Or do two trials, without sugar loading, to test the effects of practice?
Another fun variant is doing backward digit-span tests, where they have to repeat the sequence in reverse. This ties into mental processing rather than just memory.
Yep, half the sample size. Same results. I'll run your other suggestions by my son in case he wants to redo it for this years fair. Thanks.