Counting to 100 was part of my aforementioned Kindergarten test. The teacher moved beads on some rainbow abacus thingy* and I had to count along. It was excruciatingly slow to a 5 year old who was very excited about counting, and counting fast, because counting fast is better.
That was my main reason for questioning the veracity of this being a pre-first grade test. Otherwise, it’s more of a “put yourself into another person’s perspective” sort of test rather than a sequence finding one. It’s not at all unlikely, to me, that third or fourth graders could figure this out quite easily. They’re not used to pattern-finding number tests. At least I sure as hell wasn’t at that age.
This is actually a pretty fascinating test. I’d love to see it administered from K through 12 (or beyond) and see how many people can answer it within 20 seconds. I wouldn’t be surprised if there’s somewhat of a bimodal distribution.