Why there's no timer running

Fluency gets confused with speed a lot, but fast recall without understanding is brittle. Real fluency is accurate, efficient, AND flexible, and flexibility only comes from seeing why a strategy works. Kids naturally move from counting everything, to reasoning from facts they already know, to just knowing it cold. That reasoning stage is exactly what a stopwatch skips past. Showing 8 + 5 become 10 + 3 on a ten frame, or a near double as "a double, plus one," gives kids something to rebuild from when a fact slips their mind.