Spot the rule in a number series, an analogy, an odd-one-out set, a number grid, or a coded operation — five formats that all reward the same thing: testing a candidate rule against every number given, not just the first two. Every question comes with a written breakdown of exactly which rule was hiding in the numbers.
Many series look additive for the first two terms and turn out to be something else entirely by the third or fourth — always check a candidate rule against every term given before committing.
A coded-arithmetic symbol isn't multiplication or addition just because it resembles one — its exact rule has to be derived from the worked examples given, and checked against all of them, not guessed from how it looks.
The odd one out is the number that breaks a shared, testable rule — not simply the largest, smallest, or most unusual-looking number in the set.
Straight from the bank — one per difficulty tier. Reveal the answer to see the explanation you'd get in a real session.
What number comes next in the sequence: 3, 7, 11, 15, ___?
A — 19. Each term increases by a constant amount: 7−3=4, 11−7=4, 15−11=4. Continuing the pattern, the next term is 15+4=19. 18 (B) applies an increase of 3 instead of the actual common difference of 4.
6 is to 18 as 8 is to ___?
A — 24. 6 relates to 18 by a factor of 3: 6×3=18. Applying that same ×3 relationship to 8 gives 8×3=24. 20 (B) comes from adding 12 instead — a coincidental additive relationship that happens to fit this one pair, but doesn't hold as the intended rule.
If 3⋆5=11 and 4⋆2=10, using the same rule, what is 6⋆3?
A — 15. Solve for the rule using both examples: if a⋆b = pa + qb, then 3p+5q=11 and 4p+2q=10. Solving this system gives p=2 and q=1, so the rule is a⋆b = 2a+b. Applying it to 6⋆3: 2(6)+3=15. 9 (B) comes from assuming the simpler rule a⋆b=a+b fits — 6+3=9 — without checking it against both worked examples, where a+b would give 3+5=8, not 11, and 4+2=6, not 10.
Numerical reasoning spans five different formats — the fastest gains come from testing a candidate rule against every number given, not just committing after the first two.
Write out the difference, ratio, or worked-example check before choosing a rule, not just the first pair. Untimed practice is where that checking habit sticks.
Move to timed sessions once rule recognition is fast across series, analogies, odd-one-out, grids, and coded arithmetic.
Pair numerical reasoning with the visual puzzle subtopic in a mock — both test the same first-look, rule-isolation instinct, just in a different medium.
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