This is a fun, child-friendly activity by Mark David Walker, a research biologist from Sheffield. It can be done at school or at home with toy dinosaurs!
https://www.ase.org.uk/sites/default/files/SSR_June_2020_045-049_Walker_0.pdf

Accurately ascertaining the mass of a large carnivorous dinosaur is a challenging task for most students. Here, a simple method using model dinosaurs and some straightforward mathematics is provided. This is considerably more practical and safer than weighing the living dinosaur itself!

Students make scientific measurements, use mathematical concepts such as density and scale, and follow simple steps and procedures. As students (and many adults) find dinosaurs inherently interesting, this is an ideal way to integrate maths into biology.
Mark David Walker is a research biologist from Sheffield. He studied parasites of birds at Sheffield Hallam University. He has volunteered with a Sheffield-based educational charity promoting STEM education.