List

Secondary Games and Puzzles for Summer 2021

We have a challenge a day for you throughout the summer break...

Each weekday from 19 July to 31 August, a new game or puzzle will appear on this page.

After you've had a go at the day's challenge you may be able to compare your approach to the solutions we have published, which are based on students' work. 

You can also find Primary Games and Puzzles for Summer 2021.

Nine Colours
problem
Favourite

Nine Colours

Age
11 to 16
Challenge level
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Can you use small coloured cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of each colour?
Frogs
problem
Favourite

Frogs

Age
11 to 14
Challenge level
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How many moves does it take to swap over some red and blue frogs? Do you have a method?
Amazing Card Trick
problem
Favourite

Amazing Card Trick

Age
11 to 14
Challenge level
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How is it possible to predict the card?
Magic potting sheds
problem
Favourite

Magic potting sheds

Age
11 to 16
Challenge level
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Mr McGregor has a magic potting shed. Overnight, the number of plants in it doubles. He'd like to put the same number of plants in each of three gardens, planting one garden each day. Can he do it?
ACE, TWO, THREE...
problem

ACE, TWO, THREE...

Age
11 to 14
Challenge level
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Can you picture how to order the cards to reproduce Charlie's card trick for yourself?
Difference Sudoku
problem
Favourite

Difference Sudoku

Age
14 to 16
Challenge level
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Use the differences to find the solution to this Sudoku.
Connect Three
problem
Favourite

Connect Three

Age
11 to 16
Challenge level
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In this game the winner is the first to complete a row of three. Are some squares easier to land on than others?
A First Product Sudoku
problem

A First Product Sudoku

Age
7 to 14
Challenge level
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Given the products of adjacent cells, can you complete this Sudoku?
In the bag
problem
Favourite

In the bag

Age
11 to 14
Challenge level
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Can you guess the colours of the 10 marbles in the bag? Can you develop an effective strategy for reaching 1000 points in the least number of rounds?
LCM Sudoku
problem
Favourite

LCM Sudoku

Age
14 to 16
Challenge level
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Here is a Sudoku with a difference! Use information about lowest common multiples to help you solve it.
Multiples Sudoku
problem
Favourite

Multiples Sudoku

Age
11 to 14
Challenge level
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Each clue in this Sudoku is the product of the two numbers in adjacent cells.
Nice or Nasty
problem
Favourite

Nice or Nasty

Age
7 to 14
Challenge level
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There are nasty versions of this dice game but we'll start with the nice ones...
Finding factors
problem
Favourite

Finding factors

Age
14 to 16
Challenge level
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Can you find the hidden factors which multiply together to produce each quadratic expression?
Escape from the castle
problem

Escape from the castle

Age
7 to 14
Challenge level
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Skippy and Anna are locked in a room in a large castle. The key to that room, and all the other rooms, is a number. The numbers are locked away in a problem. Can you help them to get out?
Cryptarithms
problem
Favourite

Cryptarithms

Age
11 to 14
Challenge level
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Can you crack these cryptarithms?
Add to 200
problem
Favourite

Add to 200

Age
11 to 14
Challenge level
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By selecting digits for an addition grid, what targets can you make?
Gabriel's Problem
problem
Favourite

Gabriel's Problem

Age
11 to 14
Challenge level
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Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?
Alison's quilt
problem
Favourite

Alison's quilt

Age
11 to 14
Challenge level
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Nine squares are fitted together to form a rectangle. Can you find its dimensions?
Fruity Totals
problem
Favourite

Fruity Totals

Age
7 to 16
Challenge level
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In this interactivity each fruit has a hidden value. Can you deduce what each one is worth?
Treasure Hunt
problem
Favourite

Treasure Hunt

Age
7 to 14
Challenge level
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Can you find a reliable strategy for choosing coordinates that will locate the treasure in the minimum number of guesses?
The Number Jumbler
problem
Favourite

The Number Jumbler

Age
7 to 14
Challenge level
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The Number Jumbler can always work out your chosen symbol. Can you work out how?
missing multipliers
problem
Favourite

Missing Multipliers

Age
7 to 14
Challenge level
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What is the smallest number of answers you need to reveal in order to work out the missing headers?
Charlie's delightful machine
problem
Favourite

Charlie's delightful machine

Age
11 to 16
Challenge level
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Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?

Square It
problem
Favourite

Square It

Age
11 to 16
Challenge level
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Players take it in turns to choose a dot on the grid. The winner is the first to have four dots that can be joined to form a square.

Factors and Multiples Game
game
Favourite

Factors and Multiples Game

A game in which players take it in turns to choose a number. Can you block your opponent?

Dicey Operations
game
Favourite

Dicey Operations

Who said that adding, subtracting, multiplying and dividing couldn't be fun?

Countdown
game
Favourite

Countdown

Here is a chance to play a version of the classic Countdown Game.

Got It
problem
Favourite

Got It

Age
7 to 14
Challenge level
filled star filled star empty star

A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.

Product Sudoku
problem
Favourite

Product Sudoku

Age
11 to 16
Challenge level
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The clues for this Sudoku are the product of the numbers in adjacent squares.

The Remainders Game
game
Favourite

The Remainders Game

Play this game and see if you can figure out the computer's chosen number.

Diamond Collector
game
Favourite

Diamond Collector

Collect as many diamonds as you can by drawing three straight lines.