# Puzzles

## 23 December

Arrange the digits 1-9 in a 3×3 square so the 3-digits numbers formed in the rows and columns are the types of numbers given at the ends of the rows and columns.
The number in the first column is today's number.

a multiple of 4 | |||

a cube | |||

a multiple of 3 | |||

today's number | a cube | an odd number |

## 21 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10.
Today's number is the smallest number you can make with the digits in the red boxes.

+ | - | = 7 | |||

÷ | - | ÷ | |||

+ | ÷ | = 8 | |||

× | × | × | |||

+ | - | = 7 | |||

= 12 | = 5 | = 28 |

## 16 December

Arrange the digits 1-9 in a 3×3 square so that:
the median number in the first row is 6;
the median number in the second row is 3;
the mean of the numbers in the third row is 4;
the mean of the numbers in the second column is 7;
the range of the numbers in the third column is 2,
The 3-digit number in the first column is today's number.

median 6 | |||

median 3 | |||

mean 4 | |||

today's number | mean 7 | range 2 |

## 11 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10. Today's number is the product of the red digits.

+ | ÷ | = 2 | |||

+ | ÷ | ÷ | |||

÷ | ÷ | = 3 | |||

÷ | - | ÷ | |||

÷ | ÷ | = 1 | |||

= 2 | = 1 | = 1 |

## 9 December

Arrange the digits 1-9 in a 3×3 square so that:
all the digits in the first row are odd;
all the digits in the second row are even;
all the digits in the third row are multiples of 3;
all the digits in the second column are (strictly) greater than 6;
all the digits in the third column are non-prime.
The number in the first column is today's number.

all odd | |||

all even | |||

all multiples of 3 | |||

today's number | all >6 | all non-prime |

## 3 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10.
Today's number is the largest number you can make with the digits in the red boxes.

+ | + | = 21 | |||

+ | × | × | |||

+ | + | = 10 | |||

+ | ÷ | × | |||

+ | + | = 14 | |||

= 21 | = 10 | = 14 |

## 21 December

Put the digits 1 to 9 (using each digit exactly once) in the boxes so that the sums are correct. The sums should be read left to right and top to bottom ignoring the usual order of operations. For example, 4+3×2 is 14, not 10. Today's number is the smallest number you can make using the digits in the red boxes.

+ | ÷ | = 2 | |||

× | + | - | |||

× | - | = 31 | |||

+ | + | - | |||

- | × | = 42 | |||

= 37 | = 13 | = -2 |

## 16 December

Arrange the digits 1-9 in a 3×3 square so that the first row makes a triangle number, the second row's digits are all even, the third row's digits are all odd; the first column makes a square number, and the second column makes a cube number.
The number in the third column is today's number.

triangle | |||

all digits even | |||

all digits odd | |||

square | cube | today's number |