Gotta be between 20 and 30 because it’s a school zone!?! 😉
Great call, Barbara!! That’s probably the most ‘practical’ reason!! I was thinking more mathematically in an estimation sense . . . if I don’t have a calculator handy (and I probably wouldn’t in a car), how could I know the answer was between 20 & 30? (I’ll follow up with a separate e-mail.)
In the spirit of estimation, using no paper or a calculator, it’s more than 25. It’s more than 26, but just barely more than 26. It isn’t a whole number.
Since 20 squared is 400 and 30 squared is 900, one could estimate accurately that the speed limit is between 20 & 30. “A priori” knowledge tells me that 25 squared is 625, so…
When I was an engineering student in collage, one of the earliest lessons drilled into us was to estimate the answer before embarking on the quest for the precise solution. A side benefit to this is that over time, one’s ability to estimate improves, a very helpful talent that becomes almost instinctive. I’ve noticed I have a habit of estimating lots of things for which there is no actual problem; for example, the size of a crowd or how many stories high a building is.
You’re right, David – I estimate now MUCH more than I used to. And it does indeed become almost instinctive (and even more fun!)
Good point on the 25*25, Frank. On this one, I was a little slower to pick that up.
Gotta be between 20 and 30 because it’s a school zone!?! 😉
Great call, Barbara!! That’s probably the most ‘practical’ reason!! I was thinking more mathematically in an estimation sense . . . if I don’t have a calculator handy (and I probably wouldn’t in a car), how could I know the answer was between 20 & 30? (I’ll follow up with a separate e-mail.)
In the spirit of estimation, using no paper or a calculator, it’s more than 25. It’s more than 26, but just barely more than 26. It isn’t a whole number.
Since 20 squared is 400 and 30 squared is 900, one could estimate accurately that the speed limit is between 20 & 30. “A priori” knowledge tells me that 25 squared is 625, so…
When I was an engineering student in collage, one of the earliest lessons drilled into us was to estimate the answer before embarking on the quest for the precise solution. A side benefit to this is that over time, one’s ability to estimate improves, a very helpful talent that becomes almost instinctive. I’ve noticed I have a habit of estimating lots of things for which there is no actual problem; for example, the size of a crowd or how many stories high a building is.
You’re right, David – I estimate now MUCH more than I used to. And it does indeed become almost instinctive (and even more fun!)
Good point on the 25*25, Frank. On this one, I was a little slower to pick that up.