What kinds of puzzles are in Number Series?

The five puzzle types

Type	What you see	How you answer
Sequences	”What number does the ’?’ replace?” and a row of numbers	Type the missing number on the number pad and tap ✓
Outliers	”Tap the number that doesn’t belong”	Tap the odd one out
Equations	”Complete the equation:” with a ? in it	Type the number that makes it true
Transforms	”Find the transformation rule:” and pairs like 5 → 11	Work out the rule, apply it to the last number, type it
Operators	”Find the missing operator:“	Tap the operator that fits — it can be + − × ÷, a comparison (> < =), a power (^) or mod

What the rules look like

You do not need to memorise anything, but it helps to know the families the puzzles come from:

• Sequences — adding the same amount, multiplying, square and triangular numbers, Fibonacci-style (each number is the sum of the two before), powers, alternating “add then multiply”, and gaps that grow each step.
• Outliers — odd vs even, primes, squares, multiples, powers of 2, Fibonacci numbers, an arithmetic run with one intruder, and numbers whose digits add up to the same total.
• Equations — addition, subtraction, multiplication, division, two operations, squares, balancing both sides and remainders.
• Transforms — add a constant, multiply, square, double-and-add, reverse the digits, digit sums, square-minus-itself and multiply-by-the-next-number.
• Operators — a single operator, the same operator twice, comparisons, chains, powers, brackets and mod.

Hints and explanations

Where	Get a Hint	Show Explanation
Classic	Free nudge	Costs a life (can’t be used on your last life); free with Premium
Daily Challenge	One free nudge before you solve	Shown on the completion screen
Marathon	Free, once per puzzle, no health lost	Premium
Zen Practice	—	Shown after every answer
Speed Blitz, Duel, Tournament, Mastery	No hints	—

With Premium, explanations also show the working step by step (“Premium shows the working, step by step”).