World 4 · Footprints Tell Speed · 10 min · PRO
From footprint to hip height
A rule of thumb with honest error bars
PRO · Dinosaur Dig
World 4: Footprints Tell Speed is part of PRO
The first world of Dinosaur Dig is free. PRO opens the other 24 lessons in 6 worlds — simulations, quizzes and all.
PRO includes
- All 60 labs — every world, every lesson
- Practice exams and certificates
$8.33/mo, billed yearly ($99.99) · or $39.99 monthly