The chain mode of operation means that the calculator will perform calculations as they are entered (i.e., a literal “left to right” mode). Functions are performed once they have enough arguments. Some functions apply to one number only, others return values from two numbers.
To illustrate the difference between chain mode and algebraic mode, consider the following expression: 3 + 5 * 4.
Under chain mode, the solution is 32. (Obtained by first adding 5 to 3 to get 8, then multiplying 8 times 4).
Under algebraic mode, the solution is 23. (Obtained by multiplying 5 times 4, then adding 3).
Most financial calculators default to the chain mode, whereas scientific calculators tend to default to the algebraic mode.