Warning! These dinosaur bones are guaranteed to cause a lot of excitement! Cast from a durable and unique mix these bones are just waiting to be discovered.Bury them in sand soil or even water and they will instantly appeal to children's instincts to explore investigate sort collect and measure. Perfect for all those budding palaeontologists! Each bone increases in size by 20mm and can be used to introduce the concept of measurement doubling and halving.Children will love to discuss their discoveries so this set provides the perfect opportunity to develop and practise the descriptive language of measurement.The set includes 16 bones - 2 of each size: 60mm 80mm 100mm 120mm 140mm 160mm 180mm and 200mm.