Patterns AB ABB ABC — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. cat, dog, cat, dog, cat, dog
AB pattern alternates cat and dog, so dog follows the third cat in the row.
2. red, blue, blue, red, blue, blue, red, blue
ABB pattern places one red then two blues, so blue follows the new red.
3. 1, 2, 3, 1, 2, 3, 1, 2
ABC pattern repeats 1, 2, 3, so 2 always comes right after 1.
4. star, star, moon, moon, star, star, moon, moon
AABB pattern groups two stars and two moons, so a second moon comes next.
5. A, B, B, A, B, B, A, B, B
ABB pattern uses one A then two Bs, so B follows the single B.
6. circle, square, triangle, circle, square, triangle
ABC pattern repeats three shapes, so triangle follows square to finish the cycle.
7. red, red, blue, blue, red, red, blue, blue
AABB pattern groups two reds and two blues, so blue follows the first blue.
8. happy, sad, happy, sad, happy, sad, happy, sad
AB pattern alternates happy and sad, so sad always follows happy here.
9. X, Y, Z, X, Y, Z, X, Y, Z
ABC pattern uses X, Y, Z in order, so Z follows Y every cycle.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
red, blue, red, blue
→ AB pattern
AB pattern
red, blue, blue, red, blue, blue
→ ABB pattern
ABB pattern
red, blue, yellow, red, blue, yellow
→ ABC pattern
ABC pattern
red, red, blue, blue, red, red
→ AABB pattern
AABB pattern
AB uses two alternating items, ABB doubles the second, ABC uses three, AABB doubles both.