Do you know for how many years the dinosaurs ruled the Earth? Or how much the hefty Argentinosaurus weighed? Which dinosaur ran 144 per cent faster than Usain Bolt? And do you know how many hours there were in a dinosaur say? Discover the answers to all these questions and much, more more in Big Countdown: Dinosaurs.

The Big Countdown looks at popular topics and investigates the great many numbers that make them fascinating. From the mind-bogglingly large to smallest and most precious, this series helps us understand that it's not just our days that are numbered. Perfect for number-crunchers aged 9 and up.