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For younger learners

  • Early Years Foundation Stage

Number Detective

Age 5 to 11
Challenge Level Yellow star
Primary curriculum
  • Problem
  • Getting Started
  • Student Solutions
  • Teachers' Resources

Number Detective printable sheet

Calling all detectives!

You will need to think creatively, use your reasoning skills and your problem-solving strategies to find the mystery number from the table below.

  • The number has two digits.
  • Both of the digits are even.
  • The digit in the tens place is greater that the digit in the ones place.
  • The ones digit is not in the three times table.
  • The tens digit is not double the ones digit.
  • The sum of the two digits is a multiple of five.

18

86

120

42

46

64

80

8

22

83


You might now like to play the game Statement Snap or have a go at Satisfying Four Statements.

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Arrange the numbers 1 to 6 in each set of circles below. The sum of each side of the triangle should equal the number in its centre.

Grouping Goodies

Pat counts her sweets in different groups and both times she has some left over. How many sweets could she have had?

Prime Magic

Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3 grid so that all the rows and columns add up to a prime number. How many different solutions can you find?

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The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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