Patterns and Input/Output Tables — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
The pattern 3, 6, 9, 12 follows the rule add 2.
Corrected: The pattern 3, 6, 9, 12 follows the rule add 3.
Each Grade 4 pattern term is 3 more than the one before it, so the rule is add 3, not add 2.
2. Fix the sentence:
The next term in 20, 17, 14, 11 is 9.
Corrected: The next term in 20, 17, 14, 11 is 8.
The Grade 4 rule is subtract 3, so 11 minus 3 equals 8, which is the next term.
3. Fix the sentence:
In 5, 10, 15, 20 the rule is multiply by 2.
Corrected: In 5, 10, 15, 20 the rule is add 5.
Each term increases by 5, so the Grade 4 rule is add 5; multiplying by 2 would give 5, 10, 20, 40.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. The pattern 4, 8, 12, 16 follows the rule add 4 each step.
Every Grade 4 term grows by 4, so the rule is add 4.
2. The next term after 7, 14, 21, 28 is 35.
The rule is add 7, so 28 plus 7 equals 35 in this Grade 4 pattern.
3. In the pattern 30, 25, 20, 15 the rule is subtract 5.
Each Grade 4 term is 5 less than the previous one, so the rule is subtract 5.
4. The missing term in 9, 18, 27, 36 is 27.
Adding 9 to 18 gives 27, which fits the Grade 4 sequence neatly.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Describe the rule for the Grade 4 pattern 6, 12, 18, 24 and give the next term.
Sample answer: The rule is add 6 each time. Starting at 6 and adding 6 gives 12, 18, 24, and the next term is 30 because 24 plus 6 equals 30.
Identifying a constant difference is a key Grade 4 skill for extending number patterns under CCSS 4.OA.5.
2. Explain how to find the rule of a decreasing pattern like 50, 45, 40, 35 in Grade 4.
Sample answer: Subtract one term from the previous term: 50 minus 45 is 5. Each term drops by 5, so the rule is subtract 5, and the next term after 35 is 30.
Recognizing decreasing rules helps Grade 4 students describe patterns that shrink, a core CCSS 4.OA.5 idea.