What is an accurate English translation for the German "Fünftonraum". The context of its use is in fingering diagrams for the first five notes of a scale, not the pentatonic scale. The best I can come up with is "five tone interval".
The music publisher "Edition Peters" translates Czerny's "24 Übungsstücke im Fünftonraum" with "24 Five-Finger Exercises" (link).
On amazon, similar note books are sold as "Five Finger Piano" or "5-Finger Piano".
There is also a Wikipedia-entry about Five-finger exercise.
So I guess, five finger (with or without hyphen) is the English term you are looking for, although this is also the common name for several plants.