Patterns and Number Sequences — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. What comes next in 6, 12, 18, 24, 30?
The rule is add 6. 24 + 6 = 30.
2. The pattern 90, 81, 72, 63 follows the rule subtract 9. The next number is 54.
Each number decreases by 9, so the rule is subtract 9.
3. An input-output table uses the rule multiply by 5. If the input is 4, the output is 20.
4 × 5 = 20. Apply the rule multiply by 5 to the input 4.
4. The rule for the pattern 12, 16, 20, 24 is add 4.
Each number increases by 4, so the rule is add 4.
5. In the repeating pattern 5, 10, 15, 5, 10, 15, the next number is 5.
The pattern 5, 10, 15 repeats. After 15, the pattern starts over with 5.
6. If the rule is subtract 6 and the input is 30, the output is 24.
30 − 6 = 24. Apply the rule subtract 6 to the input 30.
7. In the pattern 8, 16, 24, 32, the missing number is 24.
The rule is add 8. 16 + 8 = 24.
8. In the pattern 1, 4, 9, 16, the next number is 25.
These are perfect squares: 1², 2², 3², 4². The next is 5² = 25.
9. What comes next in 100, 90, 80, 70, 60?
The rule is subtract 10. 70 − 10 = 60.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Rule: add 8, input = 12
→ 20
30
Rule: multiply by 4, input = 3
→ 12
12
Rule: subtract 5, input = 35
→ 30
23
Rule: add 9, input = 14
→ 23
20
12 + 8 = 20, 3 × 4 = 12, 35 − 5 = 30, and 14 + 9 = 23.