This may have already been posted. I use my Echo for a lot of the most common inquiries... but the one I find most usefull is it's math/calculator ability.
Alexa, what is 6.5 times 134?
Alexa, what is 18,400 divided by 230?
Alexa, what is the square root of 500?
There is a limit... I am not certain of the integer size, but if the number is too large she doesnt answer... Sorry I dont know. Like asking what is 42 Million times 364 thousand,,, etc.
Also, Alexa can only use two numbers. So you cant ask her what four plus six minus 2 is. (No algebra).
But when I'm working it's a lot faster than hitting the calculator for something basic- and Alexa has recently (perhaps a auto firmware update) - become much faster. You dont even need to skip a beat after Alexa... just carry on, and she will hear it. Don't bother waiting for the light ring. Just say it like you would to a human:
Alexa what's the weather? No pause is necessary anymore.
Rocket