a cylindrical jar of radius 6cm contains oil.how many iron spheres of radius 1.5cm should be immmersed to raise the level of oil by 2cm?
In mathematics, you don't understand things. You just get used to them.
I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.