It's no fun taking tests at a tiny lecture-hall desk, juggling a calculator, a bubble sheet, and a test booklet... under time pressure.
By strapping the calculator to your leg, you free up some of that desk space, saving you time and frustration, at minimal cost. I've encountered very little resistance from proctors - out of perhaps twenty midterms/finals and one governmental licensing test, I encountered only one objection; in that instance, the scheme failed gracefully: I simply separated the calculator from the case/strap, and used it on the table like normal.
The project is very simple. You'll need the following:
- A strap, with a length somewhat longer than the circumference of your thigh. 1" non-roll elastic (like this) works very well - the stretchiness helps keep the whole system snug, and the calculator in place, and the ribs give it a bit of resistance going through the buckle's adjustment slot.
- A set of quick-release buckles (like this), or similar alternative.
- A way of attaching the strap to the calculator. Hot glue works fine.
- A way of securing the quick-release buckle on the strap. The slickest way to do this is with stitching, so that's what I did, though the sliders which commonly come packed with quick-release buckles would work fine.
- A permissible calculator, ideally with a separable case.
With those in hand, construction can proceed:
- Add one of the buckles to the end of the strap.
- Glue (or otherwise attach) the strap to the calculator or calculator case. It is probably best to put the end of the strap with the buckle near the calculator, as this maximizes the adjustment range and puts the buckle in a easy-to-reach location.
- Add the other, adjustable, buckle to the other end of the strap.
- (optionally) Hem, or otherwise modify, the end of the strap nearest the adjustable buckle, so that said buckle cannot come off.