CAS and small numbers

[Han]

(04-22-2014 08:22 PM)Nigel (UK) Wrote:  I've tried this and it does work. The problem is that numbers in Physics are genuinely approximate, and it feels strange to enter them as exact numbers. Also, the power of ten to use depends on how many significant figures there are. It requires extra brainpower to convert 6.63e-34 to 663*10^{-36}, and 6.626e-34 to 6626*10^{-37} without getting in a muddle!

I only have experience of two other CAS systems: the TI CAS and Mathematica. Neither treat small approximate numbers in this way by default. Some numbers really are small and approximate; it would be nice to do symbolic algebra with expressions involving them. I suppose that I could define variables with the small numbers in first, but that seems rather complicated.

Rather than converting yourself, have the calculator do it. For example, for 6.626e^-34, I would type (in CAS) 6.626, hit the [ENTER] key and then the [a b/c] key, and then type * 10^(-34). Then store that using the STO menu key to whatever variable you wanted.

If you hit the [a b/c] key with the exact result, it will convert it to scientific notation.