Patterns AB ABB ABC — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. sun, moon, sun, moon, sun, moon
AB pattern alternates sun and moon, so moon comes after the third sun here.
2. A, A, B, A, A, B, A, A
AAB pattern repeats A twice then B, so A follows the third B again.
3. blue, green, green, blue, green, green, blue, green
ABB pattern has one blue then two greens, so green follows the new blue.
4. 1, 2, 3, 1, 2, 3, 1, 2, 3
ABC pattern repeats 1, 2, 3, so 3 follows 2 each cycle through.
5. cat, cat, dog, dog, cat, cat, dog, dog
AABB pattern groups two cats and two dogs, so dog follows the first dog.
6. red, red, yellow, red, red, yellow, red, red
AAB pattern repeats red twice then yellow, so red comes right after yellow.
7. circle, triangle, circle, triangle, circle, triangle
AB pattern alternates circle and triangle, so triangle follows the third circle.
8. X, Y, Z, X, Y, Z, X, Y
ABC pattern uses X, Y, Z in order, so Y always follows X here.
9. moon, moon, star, star, moon, moon, star, star
AABB pattern groups two moons and two stars, so star follows the first star.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
cat, dog, cat, dog
→ AB pattern
AB pattern
sun, moon, moon, sun, moon, moon
→ ABB pattern
ABB pattern
1, 2, 3, 1, 2, 3
→ ABC pattern
ABC pattern
A, A, B, B, A, A
→ AABB pattern
AABB pattern
Two-item alternating is AB, doubled second is ABB, three-item loop is ABC, paired is AABB.