Well, if we want to be pedantic, they never said that h is the height and r is the radius of the base circle. They could be just random numbers.
Also, since we never calculate with all the digits of pi, it is not any less weird to round to the nearest 5 and say that it’s 5, than to the nearest 0.01 and saying it’s 3.14. It just has a higher amount of rounding error.
Well, if we want to be pedantic, they never said that h is the height and r is the radius of the base circle. They could be just random numbers.
Also, since we never calculate with all the digits of pi, it is not any less weird to round to the nearest 5 and say that it’s 5, than to the nearest 0.01 and saying it’s 3.14. It just has a higher amount of rounding error.
Why are we upset by rounding to the nearest 5 for elementary schoolers when we round to 10 m/s/s for gravity in collegiate physics classes anyway?
It’s not even a bad thing to do for quick mental calculations, if you know that you will overshoot. Multiplying by 5 is easy.