HP 15c Scientific manual Nested Calculations, 7 +, 65.0000, 69.0000, 207.0000

38 Section 3: The Memory Stack, LAST X, and Data Storage

Nested Calculations

The automatic stack lift and stack drop make it possible to do nested calculations without using parentheses or storing intermediate results. A nested calculation is solved simply as a series of one- and two-number operations.

Almost every nested calculation you are likely to encounter can be done using just the four stack registers. It is usually wisest to begin the calculation at the innermost number or pair of parentheses and work outward (as you would for a manual calculation). Otherwise, you may need to place an intermediate result into a storage register. For example, consider the calculation of

	3 [4 + 5 (6 + 7)] :
Keystrokes	Display
6 v 7 + 13.0000		Intermediate result of
		(6 + 7).
5 *	65.0000	Intermediate result of
		5 (6 + 7).
4 +	69.0000	Intermediate result of
		[4 + 5 (6 + 7)].
3 *	207.0000	Final result:
		3 [4 + 5 (6 + 7)].

The following sequence illustrates the stack manipulation in this example. The stack automatically drops after each two-number calculation, and then lifts when a new number is keyed in. (For simplicity, throughout the rest of this handbook we will not show arrows between the stacks.)

T

Z

Y

X

Keys:

t

z

y

x

z

y

x

6

6

y

x

6

6

v7

y

x

6

7

y

y

x

13

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