Calling all maths detectives!
Can you solve the mysteries hidden in our carefully selected NRICH tasks?
Can you solve the mysteries hidden in our carefully selected NRICH tasks?
article
Codebreakers
This article for Primary and Secondary teachers is all about the mathematics behind solving puzzles, unravelling mysteries and breaking codes.
problem
Count the digits
Age
5 to 11
Challenge level
In this investigation we are going to count the number of 1s, 2s, 3s etc in numbers. Can you predict what will happen?
problem
I like ...
Age
5 to 7
Challenge level
Mr Gilderdale is playing a game with his class. What rule might he have chosen? How would you test your idea?
problem
Secret number
Age
5 to 7
Challenge level
Annie and Ben are playing a game with a calculator. What was Annie's secret number?
problem
What number?
Age
5 to 7
Challenge level
I am less than 25. My ones digit is twice my tens digit. My digits add up to an even number.
problem
Coded hundred square
Age
7 to 11
Challenge level
This 100 square jigsaw is written in code. It starts with 1 and ends with 100. Can you build it up?
problem
Mystery matrix
Age
7 to 11
Challenge level
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
problem
Curious number
Age
7 to 11
Challenge level
Can you order the digits from 1-3 to make a number which is divisible by 3 so when the last digit is removed it becomes a 2-figure number divisible by 2, and so on?
problem
Satisfying four statements
Age
7 to 11
Challenge level
Can you find any two-digit numbers that satisfy all of these statements?