Number Sense Puzzles
Magic squares, cryptarithms and logic puzzles that train flexible thinking.
Key idea
Magic squares, cryptarithms and logic puzzles that train flexible thinking.
In depth
Puzzles such as magic squares and cryptarithms train you to reason with number properties like parity, divisibility, and bounds rather than trial and error. Start from the most constrained spot.
Worked example
In SEND + MORE = MONEY, M must be 1 since two four-digit numbers sum to under 20,000. Then constrain the rest.
Real-world uses
- Brain training for competitions and interviews
- Magic squares and logic puzzles in classrooms
Common mistake
Guessing at random instead of using constraints.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Number Sense Puzzles?
Magic squares, cryptarithms and logic puzzles that train flexible thinking. It is a topic at the intermediate level in Arithmetic & Number Sense.
Where is Number Sense Puzzles used in real life?
Real-world examples: Brain training for competitions and interviews; Magic squares and logic puzzles in classrooms.
What should I learn before Number Sense Puzzles?
Make sure you are comfortable with Estimation with Benchmarks, the previous topic in Arithmetic & Number Sense.
What is a common mistake with Number Sense Puzzles?
Guessing at random instead of using constraints.
How can I practise Number Sense Puzzles?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Number Sense Puzzles?
Move on to Complex Word Problems next.
Related intermediate topics in Arithmetic & Number Sense
- Long Multiplication – Multiply by each digit of the multiplier, shift by place value, then add partial products.
- Long Division – Divide, multiply, subtract and bring down repeatedly to get the quotient.
- Factors and Multiples – Factors divide a number exactly; multiples are its products with whole numbers.
- Divisibility Rules – Quick tests: by 2 last digit even, by 3 digit-sum divisible by 3, by 5 ends 0/5, by 9 digit-sum divisible by 9.
- Prime Numbers – A prime has exactly two positive divisors: 1 and itself.
- Composite Numbers – Numbers greater than 1 with more than two factors.