HP 35S Scientific 35s division, correct: 2 ⎟, Description:, Then adds (5+6), First adds (3+4), Calculates (7 ⋅ 3), Calculates denominator, Calculate 2 ⎟ (3 + 10):

Keys:Display:

 

Description:

Pressing the function key produces the answer. This result can be used in further calculations.

Now study the following examples. Remember that you need to press only to separate sequentially-entered numbers, such as at the beginning of an expression. The operations themselves (, , etc.) separate subsequent numbers and save intermediate results. The last result saved is the first one retrieved as needed to carry out the calculation.

Calculate 2 ⎟ (3 + 10):

Keys:	Display:	Description:
		Calculates (3 + 10) first.
		Puts 2 before 13 so the division is
		correct: 2 ⎟ 13.
Calculate 4 ⎟ [14 + (7 ⋅ 3) – 2] :
Keys:	Display:	Description:
		Calculates (7 ⋅ 3).
		Calculates denominator.
		Puts 4 before 33 in preparation for
		division.
		Calculates 4 ⎟ 33, the answer.

Problems that have multiple parentheses can be solved in the same manner using the automatic storage of intermediate results. For example, to solve (3 + 4) ⋅ (5 + 6) on paper, you would first calculate the quantity (3 + 4). Then you would calculate (5 + 6). Finally, you would multiply the two intermediate results to get the answer.

Work through the problem the same way with the HP 35s, except that you don't have to write down intermediate answers—the calculator remembers them for you.

Keys:	Display:	Description:
		First adds (3+4)
		Then adds (5+6)

RPN: The Automatic Memory Stack 2-13