HP Prime/Commands/Guides/All About Reals
The real data type has a type ID of 0. It is the standard numeric type of the HP Prime.
Here are some examples of valid real constants:
1 1. 1.0 1e10 1e-10 1E10 1E-10 1e2.3 1ᴇ10 1ᴇ−10
Here are some examples of invalid real constants:
1.. 1e+10 1e10. 1e2e3
The largest real number is MAXREAL, or 9.99999999999ᴇ499. The smallest positive real number is MINREAL, or 1ᴇ−499. Any calculation that attempts to overflow a real value instead becomes MAXREAL. Likewise, Any calculations smaller than MINREAL becomes 0.