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CogAT Number Series Practice

Number Series questions appear in the CogAT quantitative battery at every grade level. Here is how they scale from grade 2 to high school.

Quantitative · Number Series medium Grade 2

Question 1. What number comes next? 15 25 35 45 55 ▢

  1. A65
  2. B66
  3. C75
  4. D45
  5. E55
Show answer & explanation
Answer: A — 65. The pattern is add 10 each time. 55 + 10 = 65.
Quantitative · Number Series medium Grade 5

Question 2. What number comes next? 9 10 12 5 15 0 ▢

  1. A-5
  2. B19
  3. C18
  4. D17
  5. E3
Show answer & explanation
Answer: C — 18. Two patterns take turns. Every other number (9, 12, 15) increases by 3, so the next number is 18.
Quantitative · Number Series medium Grade 9

Question 3. What number comes next? 81 100 121 144 169 ▢

  1. A195
  2. B196
  3. C197
  4. D198
  5. E194
Show answer & explanation
Answer: B — 196. These are square numbers. The next is 14 × 14 = 196.