HP 20B manual One-Number Functions and the Math Menu, RPN Stack and the Roll Down Operation

Mathematical Calculations

Figure 6 The RPN Stack and the Roll Down Operation

Pressing )performs a swap. A swap operation exchanges the numbers on Levels 1 and 2 of the stack. The )key has a small symbol on it as a reminder of the swap feature. With the numbers entered into the stack shown in the left column in Figure 7, pressing )performs a swap to the stack as shown in the right column.

Figure 7 The RPN Stack and the Swap Operation

Note: when no menu is selected, the <key performs the same function as the (key. The >key performs the inverse operation called, roll up.

One-Number Functions and the Math Menu

The key presses for the one-number mathematical functions listed in Table 2-4 below apply to all modes, Chain, Algebraic, and RPN. To execute one-number functions, with a number displayed, press the key or key combination corresponding to the operation you wish to execute. The result is displayed on the bottom line.

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