Little Scientist; Smithsonian Little Explorer Books in Order
4 books by Martha E. H. Rustad. Reading level: Grades 3.5–3.8. Lower Grades (Ages 5–8).
Series books grow with readers — but that's also the trap. Most series start at one reading level and one content intensity and drift upward over the course of the run. Little Scientist; Smithsonian Little Explorer (4 books by Martha E. H. Rustad) lands at reading level Grades 3.5–3.8, with average content intensity 1/5. Intensity stays consistent across the series — a kid who can handle the first book can generally handle the rest.
The reading-order table below lists every book with per-volume reading level and intensity badges so you can spot any escalation before it catches your reader off guard. For a deeper dive into how we score text difficulty vs. emotional weight separately — and why series readers especially benefit from that split — see our methodology page.
Content Intensity Across the Series
ConsistentContent stays at a steady intensity level throughout the series.
Little Scientist; Smithsonian Little Explorer Reading Order
| # | Title | Reading Level | Content |
|---|---|---|---|
| 1 | African Animals Martha E. H. Rustad | Level 3-4 | Gentle |
| 2 | Airplanes Martha E. H. Rustad | Level 3-4 | Gentle |
| 3 | Space Martha E. H. Rustad | Level 3-4 | Gentle |
| 4 | Volcanoes Martha E. H. Rustad | Level 3-4 | Gentle |
All Little Scientist; Smithsonian Little Explorer Books
African Animals
Martha E. H. Rustad
African Animals
Martha E. H. Rustad
Airplanes
Martha E. H. Rustad
Airplanes
Martha E. H. Rustad
Space
Martha E. H. Rustad
Space
Martha E. H. Rustad
Volcanoes
Martha E. H. Rustad
Volcanoes
Martha E. H. Rustad
Questions about the Little Scientist; Smithsonian Little Explorer series
- What reading level is the Little Scientist; Smithsonian Little Explorer series?
- The Little Scientist; Smithsonian Little Explorer series by Martha E. H. Rustad is at a Grades 3.5–3.8 reading level (average Grade 3.6). Intended for Lower Grades (Ages 5–8). There are 4 books in the series.
- What order should I read the Little Scientist; Smithsonian Little Explorer books?
- The reading-order table above lists all 4 books with per-volume reading level and intensity ratings. Start with book 1 and read in publication order unless the table indicates a different recommended order for newer readers.
- What age is the Little Scientist; Smithsonian Little Explorer series appropriate for?
- The Little Scientist; Smithsonian Little Explorer series is recommended for Lower Grades (Ages 5–8). The average content intensity is 1/5. Check the intensity trajectory above to see whether content gets heavier across the series — if it does, sensitive readers may want to stop earlier in the run.