Calculator

A calculator is a device for performing mathematical calculations, distinguished from a computer generally by a limited problem domain and an interface optimized for interactive calculation rather than programming. Calculators can be hardware or software, and mechanical or electronic, and are often built into devices such as PDAs or mobile phones.

Insurance

Promise of reimbursement in the case of loss; paid to people or companies so concerned about hazards that they have made prepayments to an insurance company.