Arithmetic Calculations With Constants - HP 12c User Manual

The diagram on page 171 illustrates how the automatic stack lift and stack drop
make chain calculations quick and error-free.
Virtually every chain calculation you are likely to encounter can be done using
only the four stack registers. However, to avoid having to store an intermediate
result in a storage register, you should begin every chain calculation at the
innermost number or pair of parentheses and then work outward — just as you
would if you were doing the calculation manually (that is, using pencil and paper).
For example, consider the calculation of
If this calculation were done from left to right — as were the (simpler) examples
under Chain Calculations on page 20 and page 22 — you would have to enter
five numbers into the calculator before doing the first operation possible (6 + 7).
But since the stack holds only four numbers, this calculation cannot be done
left-to-right. However, it can easily be done if you begin with the calculation in the
innermost pair of parentheses — again, (6 + 7).
Keystrokes
6\7+
5§
4+
3§

Arithmetic Calculations with Constants

Because the number in the T-register remains there when the stack drops, this
number can be used as a constant in arithmetic operations. To place the constant
into the T-register, key it into the display (that is, into the X-register), then press
\ three times. This also places the constant in the Y and Z-registers. Each time
an arithmetic operation is then performed — using the constant in the Y-register
and a number keyed into the displayed X-register — the constant will be
"dropped" back into the Y-register.
Example: The annual sales of solar engineering hardware your firm — currently
$84,000 — are projected to double each year for the next 3 years. Calculate the
annual sales for each of those years.
Keystrokes
2\\
\
File name: hp 12c_user's guide_English_HDPMBF12E44
Printered Date: 2005/7/29
Appendix A: The Automatic Memory Stack
3 [4 + 5 (6 + 7)]
Display
13.00
Intermediate result of (6+7).
65.00
Intermediate result of 5 (6+7).
69.00
Intermediate result of [4 + 5(6 + 7)].
207.00
Final result: 3 [4 + 5 (6 + 7)].
Display
2.00
Enters constant into Y, Z, and
T-registers.
Page: 177 of 209
Dimension: 14.8 cm x 21 cm
177