Area 2 of 6 · 5 scored questions
Number series
A sequence of numbers or letters, and one question: what comes next? The answer comes from the rule that links each term to the one before it.
- 5 of the 37 scored questions
- numbers and letters
- simple arithmetic
What it measures
What series ask of you
It’s inductive reasoning: from a few examples, find the general rule. It mixes reasoning with simple arithmetic.
- 1
Look at the gap between terms
Many series grow by a difference that follows a pattern of its own, such as adding 2, then 5, then 8.
- 2
Test more than one hypothesis
Adding, multiplying, alternating two patterns or moving through the alphabet. Whoever rules out the wrong hypothesis quickly gets there first.
- 3
Check it across the whole series
The right rule explains every term, not just the last two.
Practice question
A question like the ones in this area
It's from the practice bank, not the test. Try it before you open the reasoning.
What comes next? 6, 8, 13, 21, 32, …
- A46
- B47
- C43
- D40
- E49
See the reasoning
The differences grow by 3 each time.
In the test there's no time limit per question. In practice, the difficulty goes up when you get it right.
During the test
What helps with series
- Work out in your head the difference between each pair of terms. If the differences form another series, the answer is in it.
- If the differences don’t add up, try the ratio (multiplying) or two interleaved series.
- With letters, think of their position in the alphabet: A is 1, B is 2, and so on.
What the research says
Where this area comes from
An open format
Letter and number series are among the question types in ICAR, the public-domain battery that inspires the structure of the test (Condon and Revelle, 2014).
Only one defensible answer
Every series in the test is checked so that only one continuation follows the rule. A series that allows two reasonable readings is removed from the bank.
We don’t give an IQ per area: with only a few questions in each, the error would be too large. The report shows how many you got right and whether the area came out above, in line with, or below your overall result.
Questions
Questions about this area
Do the series involve hard math?
No. The arithmetic is simple; the difficulty lies in finding the rule. No question asks for a formula.
Can I use paper or a calculator?
The test was designed to be done in your head. Using aids changes what the result measures.
The 6 areas
Other areas of the test
-
Matrices
Find the rule that organizes a grid of shapes and apply it to the missing piece.
See the area -
Rotation
Rotate shapes mentally and recognize the same piece in another position.
See the area -
Logic
Draw valid conclusions from premises: conditions, orderings and exclusions.
See the area -
Verbal
Relationships between words and ideas: analogies, categories and syllogisms.
See the area -
Memory
Hold and use information for a few seconds: digit sequences and recall.
See the area
Ready to see how you reason?
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