A math question......

[Alex]

Originally Posted by Drince88

Yes - but you did make me smile. My Mom's theory of practical math is that everything that isn't simple arithmetic can be expressed in a ratio problem. And I've found very few examples where that wasn't true. Most of what I do know is making units cancel, which is another way of looking at ratios!

Assuming a constant rate of water being added, if you overfill your old-fashioned clawfoot bathtub what will the upward velocity of your rubber ducky be at the moment the tub reaches capacity and begins to overflow?

What? That was what constituted practical math in my calculus classes.

But yeah, for figuring out percentages I use the cross multipication method. Or if an estimate is sufficient I would have said that since 7 is approximately 1/14th of 100 then just multiply 5 by 14 to get 70 and then subtract -- to get back to 4.8 from 5 -- .2 x 14 (2.8) to get an approximate answer (67.2%) which isn't all that far from the correct number (68.6%) and is all math that is easily done mentally.