The HP 39g , HP 40g , HP 39g+ , HP 39gs , HP 40gs , and HP 39gII are algebraic graphing calculators from HP produced between 2000 and 2013.
HP 39g
HP 39g Predecessor HP 38g Successor HP 39g+
HP 40g
HP 40g Predecessor HP 38g Successor HP 40gs
HP 39g+
HP 39g+ Predecessor HP 39g Successor HP 39gs
HP 39gs
HP 39gs Predecessor HP 39g+ Successor HP 39gII Display type LCD Display size 131x64px
The HP 39gs is by far the most common calculator in the 39/40 series. They can often be found in new or lightly used condition for around 20USD.
HP 40gs
HP 39gII
The HP 39gII was a major departure from the rest of the series in terms of design, with it much more closely resembling the HP 10s and the later HP Prime .
See also 