HP 20B 3I4+, 5I6+, 3  4 5  6

		Mathematical Calculations
Table 2-2Last Number
Keys	Display	Description
+:d/		Adds 1.23 and 56.123, then divides the sum by the
		last number, 56.123. Returns results in the selected
		display format.

For more complex problems requiring two or more operations, you do not need to enter parentheses to set operational priority. Key in numbers and operations inside the parentheses first, followed by those outside of the parentheses. If a problem has more than one set of parentheses, start by working with the operations and numbers in the innermost parentheses and work out. For example, calculate:

3  4 5  6

One way to calculate this problem is to key in the numbers and operations within the parentheses first, followed by the operation outside of the parentheses. See Table 2-3.

Table 2-3Simple Arithmetic Calculations in RPN Mode

Keys	Display	Description
3I4+		Inputs the numbers and the
		operation in the first set of
		parentheses. Intermediate
		results are displayed. Note
		the (+) and (RPN)
		annunciators.

RPN Stack

Previous Value

Previous Value

Previous Value

7

5I6+	Inputs the numbers and the
	operation in the second set of
	parentheses. Intermediate
	results are displayed. Note
	the (+) annunciator.

20