If you really want to hone your skills, try using mental calculations. In
much of Europe the E6-B's are little known or used, but student pilots are
encouraged to learn simple mental calculations to solve
speed/distance/time and wind correction problems.

Here's a French link:
http://reseau.xplane.free.fr/formules/formules.html

Other contributors here certainly know English language links to the same
stuff. No need to be a math whiz - memorizing a few formulae will allow
you to do this stuff quickly in your head.

European instructors will tell you that using a calculator, mechanical or
electronic, is too much of a head-down exercise for VFR flight, and
represents a danger. . .