Yes, magnets are commonly used in calculators to help hold batteries in place or to secure the calculator cover. Magnets can also be used in certain types of stylus pens for touchscreen calculators.
Concrete calculators can be found for free at home improvement stores or websites. However, these are used as a tool only and may not be exact. In general you will need a very close estimation of the surface you need to cover.
no there are no solar calculators in india
Yes, many calculators use solar energy, but not from satellites. There is a tiny solar panel on the calculator. Cover it up with your finger and you'll see the calculator stop working.
Fitness calculators
Many of the online options for financial aid refer to students as they are aimed to help students calculate their loans and grants for university to cover things such as tuition. However, the site Bank Rate offer a few different calculators to help with things such as savings calculators and mortgage calculators so perhaps this would be a good place for you to look.
The best investment calculators, and general finance calculators, are all found online at BankRate.com. This is the best website for calculators, in my personal opinion.
simple calculators
There are some water-resistant calculators, but waterproof calculators are very hard to come by.
Primitive Calculators was created in 1978.
There are calculus calculators, such as the TI-200 Voyage.
A website called Mini Web Tool has a long list of financial calculators online. They have mortgage calculators, auto loan calculator, calculate interest calculators, credit card calculator, ROI calculators, profit to sales ratio calculator, and many more. They have calculators for almost every need.