Summation on HP 42S

[Dieter]

(09-25-2018 01:59 PM)Frido Bohn Wrote:  Write a program that multiplies natural numbers from 1 to 1000 (factorial) and overcomes the range limit of the HP42S. (The decimal approximation is a fully acceptable result.)

Simple. Add the (base 10) logs of 1...1000. The integer part of the sum is the tens exponent, 10^(fractional part) is the mantissa.

Code:

01 LBL "FCT"
02 0
03 LBL 01
04 RCL ST Y
05 LOG
06 +
07 DSE ST Y
08 GTO 01
09 IP
10 LASTX
11 FP
12 10^x
13 END

On Free42 (with 34 digit accuracy) this yields

2567
4,02387260077

So the result is 4,02387260077 E+2567.

Dieter