Missing Number Puzzle Quiz: Find the Number That Fits

This missing number puzzle quiz asks you to find the number that completes ten puzzles, from gaps in number series and Fibonacci-style rows to number machines, pairs and a classic magic square like the Lo Shu square of ancient China. Work out the rule, then choose the number that fits.

Start Missing Number Puzzle Quiz

🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 90 Seconds

Question 1 / 10 Time: 90s

Series
Which number is missing: 5, 11, ?, 29, 41?
Machines
A number machine turns 2 into 5, 4 into 17 and 6 into 37. What does it turn 8 into?
Pairs
12 is to 144 as 9 is to what?
Rows
In this row, each number is the sum of the two before it: 3, 7, ?, 17, 27, 44. What is missing?
Totals
Three numbers around a circle add up to the number in the middle. The numbers are 6, 9 and ?, and the middle is 24. What is missing?
Series
Which number is missing: 2, 6, 12, 20, ?, 42?
Equations
Which number makes this true: 7 times ? minus 5 equals 44?
Magic squares
In a 3 by 3 magic square, every row adds up to 15. One row reads 8, 1, ?. What is missing?
Series
Which number is missing: 1, 2, 4, 7, 11, ?, 22?
Triangles
In each triangle, the middle number is the product of the three corners. The corners are 3, 4 and 5. What is the middle number?

Explanations: answer key for all 10 questions

Q1: Which number is missing: 5, 11, ?, 29, 41?
Answer: 19
The gaps grow by two each time: plus 6, plus 8, plus 10 and plus 12. So the missing number is 11 plus 8, which is 19.
Q2: A number machine turns 2 into 5, 4 into 17 and 6 into 37. What does it turn 8 into?
Answer: 65
The rule is to square the number and add one: 2 squared plus 1 is 5, and 8 squared plus 1 is 65.
Q3: 12 is to 144 as 9 is to what?
Answer: 81
144 is 12 times 12. In the same way, 9 times 9 is 81. Both pairs link a number to its square.
Q4: In this row, each number is the sum of the two before it: 3, 7, ?, 17, 27, 44. What is missing?
Answer: 10
3 plus 7 makes 10, and 7 plus 10 makes 17, which matches the row. This is the same rule as the famous Fibonacci sequence.
Q5: Three numbers around a circle add up to the number in the middle. The numbers are 6, 9 and ?, and the middle is 24. What is missing?
Answer: 9
6 plus 9 is 15, and 24 minus 15 is 9. Circle puzzles like this are popular in puzzle books and newspapers.
Q6: Which number is missing: 2, 6, 12, 20, ?, 42?
Answer: 30
Each number is a whole number times the next one: 1 times 2, 2 times 3, 3 times 4, 4 times 5, then 5 times 6, which is 30.
Q7: Which number makes this true: 7 times ? minus 5 equals 44?
Answer: 7
Add 5 to 44 to get 49, then divide by 7. The missing number is 7.
Q8: In a 3 by 3 magic square, every row adds up to 15. One row reads 8, 1, ?. What is missing?
Answer: 6
8 plus 1 is 9, and 15 minus 9 is 6. In a magic square, rows, columns and diagonals all have the same total.
Q9: Which number is missing: 1, 2, 4, 7, 11, ?, 22?
Answer: 16
The gaps grow by one each time: plus 1, plus 2, plus 3, plus 4, plus 5 and plus 6. So 11 plus 5 gives 16, and 16 plus 6 gives 22.
Q10: In each triangle, the middle number is the product of the three corners. The corners are 3, 4 and 5. What is the middle number?
Answer: 60
Multiplying the corners gives 3 times 4 times 5, which is 60. Adding them would give only 12, so read the rule carefully.

Missing Number Puzzle Quiz – Filling the Gaps

Missing number puzzles show a pattern with one number left out and ask you to find it. They appear in school worksheets, puzzle books, newspapers and aptitude tests. Unlike plain arithmetic, they ask you to discover a rule first, then use it to fill the gap. That makes them a great test of pattern recognition and logical thinking.

The rule can take many forms. In number series, look at the gaps between numbers and see whether they stay the same, grow steadily or follow another pattern. In number machines, test whether the rule adds, multiplies, squares or combines several steps. In shape puzzles, the numbers in the corners may be added, multiplied or compared with a number in the center.

Magic squares are among the oldest number puzzles. According to Chinese legend, the Lo Shu square appeared on the back of a turtle emerging from the Luo River thousands of years ago. It arranges the numbers 1 to 9 in a 3 by 3 grid so that every row, column and diagonal adds up to 15. Magic squares later spread to India, the Islamic world and Europe.

Rows where each number is the sum of the two before follow the same rule as the Fibonacci sequence, though they can start with any two numbers. Products such as 2, 6, 12 and 20 come from multiplying neighboring whole numbers.

A good habit is to test your rule on every number in the puzzle, not just the first two, before choosing an answer.

Missing number puzzles are a fun daily brain exercise for both children and adults.

What This Quiz Teaches

This quiz is perfect for math fans, students and puzzle lovers.

How to find the rule in a missing number puzzle
Number series with growing gaps
Number machines and pairs
Fibonacci-style rows
Magic squares and the Lo Shu square
Shape puzzles with sums and products

Quick Facts About Number Puzzles

The Lo Shu square has the number 5 in the center.
Albrecht Dürer included a magic square in his 1514 engraving Melencolia I.
Kakuro is a crossword-style number puzzle popular in Japan.
KenKen puzzles were invented by a Japanese teacher in 2004.
Number puzzles appear in many job aptitude tests.
Benjamin Franklin enjoyed creating magic squares.