CogAT® Question Type: Number Series Example & Tips

In this post, we start with an overview of "Number Series" question types. We also provide a sample question, accompanied by tips and strategies that every student can use to perform successfully on "Number Series" questions during the official CogAT® exam.

Number Series questions are part of the quantitative battery on the CogAT. Number Puzzles and Number Analogies are the other two subtests in this battery.

Number Series Questions: What To Expect?

Students are given a series of numbers following a pattern. They must determine what number should come next in the series.

K-2 students are given images of beads on an abacus. Based on the images, they must determine what the next abacus in the series should look like.

How Many Number Series Questions Are On The Test?

The amount of number series questions on the test depends on the age of the student and the test level, as shown by the table below.

Number Series
Level Number of Questions Grade Level
Approximate Age
Level 5/6 14 Kindergarten 5/6 Years
Level 7 16 1st Grade 7 Years
Level 8 18 2nd Grade 8 Years
Level 9 18 3rd Grade 9 Years
Level 10 18 4th Grade 10 Years
Level 11 18 5th Grade 11 Years
Level 12 18 6th Grade 12 Years
Level 13-18 18 7th-12th Grade 13-18 Years

Number Series: Sample Question

The example below is a CogAT Level 11 Number Series question.


Correct Answer: D

In this series, letters and two-digit numbers alternate, with 17 being the last number just before the question mark. This means that the missing term that follows must bea letter. Therefore, we can eliminate choices B and E, which are numbers.

If we separate the numbers from letters, we see that while the numbers grow by 1, the letters progress by skipping every other letter starting from D. Therefore, the letter that comes after L must be N. The correct answer is choice D.

Number Series:Tips and Strategies

To correctly answer these questions, your child will need the ability to identify patterns in a sequence of numbers or letters and supply the missing item.

Because your child may not have much formal academic experience with this question type, it is important to practice working with these questions beforehand.

It may be helpful to model how to approach the questions for your child. Read the question aloud, and then do a “think-aloud,” talking through your thought process as you solve the problem.

As your child completes questions, have him explain how he arrived at the answer. If the answer is correct, this will reinforce his logical reasoning skills. If the answer is incorrect, this gives you the opportunity to correct misconceptions and suggest a better approach.

You can also find workbooks or games related to number patterns and sequences to help your child further practice test concepts in an engaging manner.

Tell your child not to panic if he struggles on the test. Instead, make an educated guess, take a deep breath, and move on to avoid wasting precious time.

What's Next?

Help your child become familiar with the questions on this challenging exam by downloading a free CogAT practice test.

Learn more about other quantitative question types on the CoGAT, including Number Puzzles, and Number Analogies.

Also see critical teaching tips that cover other areas of the CogAT, including the nonverbal battery and the verbal battery.

If you think you need more information and guidance about the CogAT, check out our ultimate guide on the test, and our in-depth article on CogAT scores.

Also, learn everything you need to know about other tests that measure a child’s potential to learn in school, like the NNAT or the OLSAT.