Patterns and Number Sequences — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. The pattern 2, 5, 8, 11 follows the rule add 3. The next number is 14.
From 2 to 5 is a jump of 3, and the same jump of 3 happens at every step. Adding 3 to 11 gives 14, so the rule is add 3.
2. What comes next in 7, 14, 21, 28, 35?
Skip-counting by 7 gives 7, 14, 21, 28, 35. Adding 7 to 28 lands on 35.
3. The pattern 80, 72, 64, 56 follows the rule subtract 8. The next number is 48.
From 80 to 72 is a drop of 8, and the same drop of 8 happens between every pair of numbers. So the rule is subtract 8.
4. An input-output table uses the rule multiply by 2. If the input is 6, the output is 12.
Multiply the input by 2: 6 × 2 = 12, which is the output.
5. In the pattern 3, 6, 12, 24, each number is multiplied by 2.
Each number doubles: 3 × 2 = 6, 6 × 2 = 12, 12 × 2 = 24. So each number is multiplied by 2.
6. If the rule is add 7 and the input is 15, the output is 22.
Add 7 to the input of 15: 15 + 7 = 22, which is the output.
7. In the pattern 10, 20, 30, 40, the missing number is 20. The rule is add 10.
From 10 to 30 is a jump of 20, but each step adds the same amount. The number that fits between 10 and 30 is 20, and the rule is add 10 each step (so 10, 20, 30, 40).
8. What comes next in 60, 55, 50, 45, 40?
Each number drops by 5: 60, 55, 50, 45, 40. Subtracting 5 from 45 gives 40.
9. In the repeating pattern 1, 2, 3, 1, 2, 3, 1, the next number is 2.
The group 1, 2, 3 keeps repeating. After the second 1 comes 2 again, just like at the start of the group.
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 4, input = 8
→ 12
15
Rule: subtract 3, input = 20
→ 17
20
Rule: multiply by 3, input = 5
→ 15
12
Rule: add 9, input = 11
→ 20
17
Apply each rule to its input: 8 + 4 = 12, 20 − 3 = 17, 5 × 3 = 15, and 11 + 9 = 20. Each pairing matches an input-rule combination to its output.