For educators Six books on one animal, from a child's first book to read alone to popular science for adults. A class can study the same facts with every reader in a book they can manage.
Octopus
The six folds compared
Measure Fold 1, ages 4 to 6 FOLD 1 AGES 4–6 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8 Fold 3, ages 8 to 10 FOLD 3 AGES 8–10 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12 Fold 5, ages 12 and up FOLD 5 AGES 12+ Fold 6, ages 12 and up FOLD 6 AGES 12+ Ages 4–6 6–8 8–10 10–12 12+ 12+ Reading grade Pre-K–K K–2 1–2 2–4 4–7 not graded Stage First Reader Read Together Early Reader Explorer Field Guide Deep Dive Book 6 × 9 in, 24 pp 8.5 × 8.5 in, 32 pp 6 × 9 in, 32 pp 8 × 10 in, 40 pp 8 × 10 in, 48 pp 6 × 9 in, 64 pp Words 109 257 548 2,182 5,492 7,734 Words a sentence 3.8 4.2 5.9 7.9 10.2 18.7 Longest sentence 7 words 12 words 10 words 19 words 28 words 42 words Flesch–Kincaid grade 0.7 1.9 read aloud 1.7 3.9 6.4 9.8
Fold 1, ages 4 to 6 FOLD 1 AGES 4–6
Ages 4–6
Reading grade Pre-K–K
Stage First Reader
Book 6 × 9 in, 24 pp
Words 109
Words a sentence 3.8
Longest sentence 7 words
Flesch–Kincaid grade 0.7 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8
Ages 6–8
Reading grade K–2
Stage Read Together
Book 8.5 × 8.5 in, 32 pp
Words 257
Words a sentence 4.2
Longest sentence 12 words
Flesch–Kincaid grade 1.9 read aloud Fold 3, ages 8 to 10 FOLD 3 AGES 8–10
Ages 8–10
Reading grade 1–2
Stage Early Reader
Book 6 × 9 in, 32 pp
Words 548
Words a sentence 5.9
Longest sentence 10 words
Flesch–Kincaid grade 1.7 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12
Ages 10–12
Reading grade 2–4
Stage Explorer
Book 8 × 10 in, 40 pp
Words 2,182
Words a sentence 7.9
Longest sentence 19 words
Flesch–Kincaid grade 3.9 Fold 5, ages 12 and up FOLD 5 AGES 12+
Ages 12+
Reading grade 4–7
Stage Field Guide
Book 8 × 10 in, 48 pp
Words 5,492
Words a sentence 10.2
Longest sentence 28 words
Flesch–Kincaid grade 6.4 Fold 6, ages 12 and up FOLD 6 AGES 12+
Ages 12+
Reading grade not graded
Stage Deep Dive
Book 6 × 9 in, 64 pp
Words 7,734
Words a sentence 18.7
Longest sentence 42 words
Flesch–Kincaid grade 9.8 Teaching with the octopus set
Penguin
The six folds compared
Measure Fold 1, ages 4 to 6 FOLD 1 AGES 4–6 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8 Fold 3, ages 8 to 10 FOLD 3 AGES 8–10 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12 Fold 5, ages 12 and up FOLD 5 AGES 12+ Fold 6, ages 12 and up FOLD 6 AGES 12+ Ages 4–6 6–8 8–10 10–12 12+ 12+ Reading grade Pre-K–K K–2 1–2 2–4 4–7 not graded Stage First Reader Read Together Early Reader Explorer Field Guide Deep Dive Book 6 × 9 in, 24 pp 8.5 × 8.5 in, 32 pp 6 × 9 in, 32 pp 8 × 10 in, 40 pp 8 × 10 in, 48 pp 6 × 9 in, 64 pp Words 105 223 492 2,181 5,046 8,057 Words a sentence 3.6 4.6 6.1 7.3 10.2 14.8 Longest sentence 7 words 11 words 10 words 15 words 22 words 32 words Flesch–Kincaid grade -0.9 -0.2 read aloud 0.5 3.2 6.4 10.7
Fold 1, ages 4 to 6 FOLD 1 AGES 4–6
Ages 4–6
Reading grade Pre-K–K
Stage First Reader
Book 6 × 9 in, 24 pp
Words 105
Words a sentence 3.6
Longest sentence 7 words
Flesch–Kincaid grade -0.9 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8
Ages 6–8
Reading grade K–2
Stage Read Together
Book 8.5 × 8.5 in, 32 pp
Words 223
Words a sentence 4.6
Longest sentence 11 words
Flesch–Kincaid grade -0.2 read aloud Fold 3, ages 8 to 10 FOLD 3 AGES 8–10
Ages 8–10
Reading grade 1–2
Stage Early Reader
Book 6 × 9 in, 32 pp
Words 492
Words a sentence 6.1
Longest sentence 10 words
Flesch–Kincaid grade 0.5 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12
Ages 10–12
Reading grade 2–4
Stage Explorer
Book 8 × 10 in, 40 pp
Words 2,181
Words a sentence 7.3
Longest sentence 15 words
Flesch–Kincaid grade 3.2 Fold 5, ages 12 and up FOLD 5 AGES 12+
Ages 12+
Reading grade 4–7
Stage Field Guide
Book 8 × 10 in, 48 pp
Words 5,046
Words a sentence 10.2
Longest sentence 22 words
Flesch–Kincaid grade 6.4 Fold 6, ages 12 and up FOLD 6 AGES 12+
Ages 12+
Reading grade not graded
Stage Deep Dive
Book 6 × 9 in, 64 pp
Words 8,057
Words a sentence 14.8
Longest sentence 32 words
Flesch–Kincaid grade 10.7 Teaching with the penguin set
Wolf
The six folds compared
Measure Fold 1, ages 4 to 6 FOLD 1 AGES 4–6 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8 Fold 3, ages 8 to 10 FOLD 3 AGES 8–10 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12 Fold 5, ages 12 and up FOLD 5 AGES 12+ Fold 6, ages 12 and up FOLD 6 AGES 12+ Ages 4–6 6–8 8–10 10–12 12+ 12+ Reading grade Pre-K–K K–2 1–2 2–4 4–7 not graded Stage First Reader Read Together Early Reader Explorer Field Guide Deep Dive Book 6 × 9 in, 24 pp 8.5 × 8.5 in, 32 pp 6 × 9 in, 32 pp 8 × 10 in, 40 pp 8 × 10 in, 48 pp 6 × 9 in, 56 pp Words 108 253 504 2,164 5,356 8,904 Words a sentence 3.7 4.4 6.8 7.5 10.8 16.8 Longest sentence 7 words 11 words 10 words 18 words 26 words 43 words Flesch–Kincaid grade -2.3 -0.5 read aloud -0.7 2.6 6.5 9.8
Fold 1, ages 4 to 6 FOLD 1 AGES 4–6
Ages 4–6
Reading grade Pre-K–K
Stage First Reader
Book 6 × 9 in, 24 pp
Words 108
Words a sentence 3.7
Longest sentence 7 words
Flesch–Kincaid grade -2.3 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8
Ages 6–8
Reading grade K–2
Stage Read Together
Book 8.5 × 8.5 in, 32 pp
Words 253
Words a sentence 4.4
Longest sentence 11 words
Flesch–Kincaid grade -0.5 read aloud Fold 3, ages 8 to 10 FOLD 3 AGES 8–10
Ages 8–10
Reading grade 1–2
Stage Early Reader
Book 6 × 9 in, 32 pp
Words 504
Words a sentence 6.8
Longest sentence 10 words
Flesch–Kincaid grade -0.7 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12
Ages 10–12
Reading grade 2–4
Stage Explorer
Book 8 × 10 in, 40 pp
Words 2,164
Words a sentence 7.5
Longest sentence 18 words
Flesch–Kincaid grade 2.6 Fold 5, ages 12 and up FOLD 5 AGES 12+
Ages 12+
Reading grade 4–7
Stage Field Guide
Book 8 × 10 in, 48 pp
Words 5,356
Words a sentence 10.8
Longest sentence 26 words
Flesch–Kincaid grade 6.5 Fold 6, ages 12 and up FOLD 6 AGES 12+
Ages 12+
Reading grade not graded
Stage Deep Dive
Book 6 × 9 in, 56 pp
Words 8,904
Words a sentence 16.8
Longest sentence 43 words
Flesch–Kincaid grade 9.8 Teaching with the wolf set
Otter
The six folds compared
Measure Fold 1, ages 4 to 6 FOLD 1 AGES 4–6 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8 Fold 3, ages 8 to 10 FOLD 3 AGES 8–10 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12 Fold 5, ages 12 and up FOLD 5 AGES 12+ Fold 6, ages 12 and up FOLD 6 AGES 12+ Ages 4–6 6–8 8–10 10–12 12+ 12+ Reading grade Pre-K–K K–2 1–2 2–4 4–7 not graded Stage First Reader Read Together Early Reader Explorer Field Guide Deep Dive Book 6 × 9 in, 24 pp 8.5 × 8.5 in, 32 pp 6 × 9 in, 32 pp 8 × 10 in, 40 pp 8 × 10 in, 48 pp 6 × 9 in, 58 pp Words 108 256 534 2,123 4,529 7,296 Words a sentence 3.4 5 6.5 8.3 10.6 18.3 Longest sentence 7 words 12 words 10 words 18 words 28 words 44 words Flesch–Kincaid grade -0.2 1.1 read aloud 0.8 3.7 5.7 9.4
Fold 1, ages 4 to 6 FOLD 1 AGES 4–6
Ages 4–6
Reading grade Pre-K–K
Stage First Reader
Book 6 × 9 in, 24 pp
Words 108
Words a sentence 3.4
Longest sentence 7 words
Flesch–Kincaid grade -0.2 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8
Ages 6–8
Reading grade K–2
Stage Read Together
Book 8.5 × 8.5 in, 32 pp
Words 256
Words a sentence 5
Longest sentence 12 words
Flesch–Kincaid grade 1.1 read aloud Fold 3, ages 8 to 10 FOLD 3 AGES 8–10
Ages 8–10
Reading grade 1–2
Stage Early Reader
Book 6 × 9 in, 32 pp
Words 534
Words a sentence 6.5
Longest sentence 10 words
Flesch–Kincaid grade 0.8 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12
Ages 10–12
Reading grade 2–4
Stage Explorer
Book 8 × 10 in, 40 pp
Words 2,123
Words a sentence 8.3
Longest sentence 18 words
Flesch–Kincaid grade 3.7 Fold 5, ages 12 and up FOLD 5 AGES 12+
Ages 12+
Reading grade 4–7
Stage Field Guide
Book 8 × 10 in, 48 pp
Words 4,529
Words a sentence 10.6
Longest sentence 28 words
Flesch–Kincaid grade 5.7 Fold 6, ages 12 and up FOLD 6 AGES 12+
Ages 12+
Reading grade not graded
Stage Deep Dive
Book 6 × 9 in, 58 pp
Words 7,296
Words a sentence 18.3
Longest sentence 44 words
Flesch–Kincaid grade 9.4 Teaching with the otter set
Scorpion
The six folds compared
Measure Fold 1, ages 4 to 6 FOLD 1 AGES 4–6 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8 Fold 3, ages 8 to 10 FOLD 3 AGES 8–10 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12 Fold 5, ages 12 and up FOLD 5 AGES 12+ Fold 6, ages 12 and up FOLD 6 AGES 12+ Ages 4–6 6–8 8–10 10–12 12+ 12+ Reading grade Pre-K–K K–2 1–2 2–4 4–7 not graded Stage First Reader Read Together Early Reader Explorer Field Guide Deep Dive Book 6 × 9 in, 24 pp 8.5 × 8.5 in, 32 pp 6 × 9 in, 32 pp 8 × 10 in, 40 pp 8 × 10 in, 48 pp 6 × 9 in, 60 pp Words 101 212 458 2,126 4,866 8,496 Words a sentence 3.6 5.2 5.5 7.4 9.3 15.3 Longest sentence 6 words 9 words 10 words 16 words 20 words 37 words Flesch–Kincaid grade -0.3 3.0 read aloud 2.0 4.0 7.1 12.2
Fold 1, ages 4 to 6 FOLD 1 AGES 4–6
Ages 4–6
Reading grade Pre-K–K
Stage First Reader
Book 6 × 9 in, 24 pp
Words 101
Words a sentence 3.6
Longest sentence 6 words
Flesch–Kincaid grade -0.3 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8
Ages 6–8
Reading grade K–2
Stage Read Together
Book 8.5 × 8.5 in, 32 pp
Words 212
Words a sentence 5.2
Longest sentence 9 words
Flesch–Kincaid grade 3.0 read aloud Fold 3, ages 8 to 10 FOLD 3 AGES 8–10
Ages 8–10
Reading grade 1–2
Stage Early Reader
Book 6 × 9 in, 32 pp
Words 458
Words a sentence 5.5
Longest sentence 10 words
Flesch–Kincaid grade 2.0 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12
Ages 10–12
Reading grade 2–4
Stage Explorer
Book 8 × 10 in, 40 pp
Words 2,126
Words a sentence 7.4
Longest sentence 16 words
Flesch–Kincaid grade 4.0 Fold 5, ages 12 and up FOLD 5 AGES 12+
Ages 12+
Reading grade 4–7
Stage Field Guide
Book 8 × 10 in, 48 pp
Words 4,866
Words a sentence 9.3
Longest sentence 20 words
Flesch–Kincaid grade 7.1 Fold 6, ages 12 and up FOLD 6 AGES 12+
Ages 12+
Reading grade not graded
Stage Deep Dive
Book 6 × 9 in, 60 pp
Words 8,496
Words a sentence 15.3
Longest sentence 37 words
Flesch–Kincaid grade 12.2 Teaching with the scorpion set
Maine Coon
The six folds compared
Measure Fold 1, ages 4 to 6 FOLD 1 AGES 4–6 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8 Fold 3, ages 8 to 10 FOLD 3 AGES 8–10 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12 Fold 5, ages 12 and up FOLD 5 AGES 12+ Fold 6, ages 12 and up FOLD 6 AGES 12+ Ages 4–6 6–8 8–10 10–12 12+ 12+ Reading grade Pre-K–K K–2 1–2 2–4 4–7 not graded Stage First Reader Read Together Early Reader Explorer Field Guide Deep Dive Book 6 × 9 in, 24 pp 8.5 × 8.5 in, 32 pp 6 × 9 in, 32 pp 8 × 10 in, 40 pp 8 × 10 in, 48 pp 6 × 9 in, 58 pp Words 109 255 524 2,138 5,159 7,169 Words a sentence 3.3 4.9 6.7 9 12.3 20 Longest sentence 7 words 12 words 10 words 20 words 29 words 44 words Flesch–Kincaid grade -2.5 -0.1 read aloud -0.5 2.8 4.9 9.6
Fold 1, ages 4 to 6 FOLD 1 AGES 4–6
Ages 4–6
Reading grade Pre-K–K
Stage First Reader
Book 6 × 9 in, 24 pp
Words 109
Words a sentence 3.3
Longest sentence 7 words
Flesch–Kincaid grade -2.5 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8
Ages 6–8
Reading grade K–2
Stage Read Together
Book 8.5 × 8.5 in, 32 pp
Words 255
Words a sentence 4.9
Longest sentence 12 words
Flesch–Kincaid grade -0.1 read aloud Fold 3, ages 8 to 10 FOLD 3 AGES 8–10
Ages 8–10
Reading grade 1–2
Stage Early Reader
Book 6 × 9 in, 32 pp
Words 524
Words a sentence 6.7
Longest sentence 10 words
Flesch–Kincaid grade -0.5 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12
Ages 10–12
Reading grade 2–4
Stage Explorer
Book 8 × 10 in, 40 pp
Words 2,138
Words a sentence 9
Longest sentence 20 words
Flesch–Kincaid grade 2.8 Fold 5, ages 12 and up FOLD 5 AGES 12+
Ages 12+
Reading grade 4–7
Stage Field Guide
Book 8 × 10 in, 48 pp
Words 5,159
Words a sentence 12.3
Longest sentence 29 words
Flesch–Kincaid grade 4.9 Fold 6, ages 12 and up FOLD 6 AGES 12+
Ages 12+
Reading grade not graded
Stage Deep Dive
Book 6 × 9 in, 58 pp
Words 7,169
Words a sentence 20
Longest sentence 44 words
Flesch–Kincaid grade 9.6 Teaching with the maine coon set
tabby cat
The six folds compared
Measure Fold 1, ages 4 to 6 FOLD 1 AGES 4–6 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8 Fold 3, ages 8 to 10 FOLD 3 AGES 8–10 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12 Fold 5, ages 12 and up FOLD 5 AGES 12+ Fold 6, ages 12 and up FOLD 6 AGES 12+ Ages 4–6 6–8 8–10 10–12 12+ 12+ Reading grade Pre-K–K K–2 1–2 2–4 4–7 not graded Stage First Reader Read Together Early Reader Explorer Field Guide Deep Dive Book 6 × 9 in, 24 pp 8.5 × 8.5 in, 32 pp 6 × 9 in, 32 pp 8 × 10 in, 40 pp 8 × 10 in, 48 pp 6 × 9 in, 64 pp Words 107 249 530 2,103 4,671 7,345 Words a sentence 3.3 5.8 6.5 8.4 10.9 19.3 Longest sentence 7 words 12 words 10 words 19 words 27 words 45 words Flesch–Kincaid grade -1.7 0.9 read aloud -0.1 2.7 4.7 9.3
Fold 1, ages 4 to 6 FOLD 1 AGES 4–6
Ages 4–6
Reading grade Pre-K–K
Stage First Reader
Book 6 × 9 in, 24 pp
Words 107
Words a sentence 3.3
Longest sentence 7 words
Flesch–Kincaid grade -1.7 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8
Ages 6–8
Reading grade K–2
Stage Read Together
Book 8.5 × 8.5 in, 32 pp
Words 249
Words a sentence 5.8
Longest sentence 12 words
Flesch–Kincaid grade 0.9 read aloud Fold 3, ages 8 to 10 FOLD 3 AGES 8–10
Ages 8–10
Reading grade 1–2
Stage Early Reader
Book 6 × 9 in, 32 pp
Words 530
Words a sentence 6.5
Longest sentence 10 words
Flesch–Kincaid grade -0.1 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12
Ages 10–12
Reading grade 2–4
Stage Explorer
Book 8 × 10 in, 40 pp
Words 2,103
Words a sentence 8.4
Longest sentence 19 words
Flesch–Kincaid grade 2.7 Fold 5, ages 12 and up FOLD 5 AGES 12+
Ages 12+
Reading grade 4–7
Stage Field Guide
Book 8 × 10 in, 48 pp
Words 4,671
Words a sentence 10.9
Longest sentence 27 words
Flesch–Kincaid grade 4.7 Fold 6, ages 12 and up FOLD 6 AGES 12+
Ages 12+
Reading grade not graded
Stage Deep Dive
Book 6 × 9 in, 64 pp
Words 7,345
Words a sentence 19.3
Longest sentence 45 words
Flesch–Kincaid grade 9.3 Teaching with the tabby cat set
pigeon
The six folds compared
Measure Fold 1, ages 4 to 6 FOLD 1 AGES 4–6 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8 Fold 3, ages 8 to 10 FOLD 3 AGES 8–10 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12 Fold 5, ages 12 and up FOLD 5 AGES 12+ Fold 6, ages 12 and up FOLD 6 AGES 12+ Ages 4–6 6–8 8–10 10–12 12+ 12+ Reading grade Pre-K–K K–2 1–2 2–4 4–7 not graded Stage First Reader Read Together Early Reader Explorer Field Guide Deep Dive Book 6 × 9 in, 24 pp 8.5 × 8.5 in, 32 pp 6 × 9 in, 32 pp 8 × 10 in, 40 pp 8 × 10 in, 48 pp 6 × 9 in, 62 pp Words 108 259 548 2,152 4,470 7,558 Words a sentence 3 6.2 6.2 8.1 10.7 17.5 Longest sentence 6 words 12 words 10 words 18 words 25 words 42 words Flesch–Kincaid grade -0.8 2.9 read aloud 0.8 3.8 4.8 9.2
Fold 1, ages 4 to 6 FOLD 1 AGES 4–6
Ages 4–6
Reading grade Pre-K–K
Stage First Reader
Book 6 × 9 in, 24 pp
Words 108
Words a sentence 3
Longest sentence 6 words
Flesch–Kincaid grade -0.8 Fold 2, ages 6 to 8 FOLD 2 AGES 6–8
Ages 6–8
Reading grade K–2
Stage Read Together
Book 8.5 × 8.5 in, 32 pp
Words 259
Words a sentence 6.2
Longest sentence 12 words
Flesch–Kincaid grade 2.9 read aloud Fold 3, ages 8 to 10 FOLD 3 AGES 8–10
Ages 8–10
Reading grade 1–2
Stage Early Reader
Book 6 × 9 in, 32 pp
Words 548
Words a sentence 6.2
Longest sentence 10 words
Flesch–Kincaid grade 0.8 Fold 4, ages 10 to 12 FOLD 4 AGES 10–12
Ages 10–12
Reading grade 2–4
Stage Explorer
Book 8 × 10 in, 40 pp
Words 2,152
Words a sentence 8.1
Longest sentence 18 words
Flesch–Kincaid grade 3.8 Fold 5, ages 12 and up FOLD 5 AGES 12+
Ages 12+
Reading grade 4–7
Stage Field Guide
Book 8 × 10 in, 48 pp
Words 4,470
Words a sentence 10.7
Longest sentence 25 words
Flesch–Kincaid grade 4.8 Fold 6, ages 12 and up FOLD 6 AGES 12+
Ages 12+
Reading grade not graded
Stage Deep Dive
Book 6 × 9 in, 62 pp
Words 7,558
Words a sentence 17.5
Longest sentence 42 words
Flesch–Kincaid grade 9.2 Teaching with the pigeon set