Reading Metrics
Grade Level
Middle Grades (MG 4-8)
Book Level
8.7
Points
0.5
Fiction/Nonfiction
Nonfiction
Word Count
2370
Points per Word
0.000211
Page Count
32
Points per Page
0.015625
Series
Development of the Earth
Description
Although the earliest mammals were small in size and often fell prey to large reptiles, this book tells how these creatures eventually became the rulers of the earth.