# Resources tagged with: Working systematically

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### There are 132 results

Broad Topics > Thinking Mathematically > Working systematically

##### Age 11 to 16Challenge Level

This is a variation of sudoku which contains a set of special clue-numbers. Each set of 4 small digits stands for the numbers in the four cells of the grid adjacent to this set.

### Intersection Sudoku 1

##### Age 11 to 16Challenge Level

A Sudoku with a twist.

##### Age 11 to 16Challenge Level

Four numbers on an intersection that need to be placed in the surrounding cells. That is all you need to know to solve this sudoku.

### Consecutive Negative Numbers

##### Age 11 to 14Challenge Level

Do you notice anything about the solutions when you add and/or subtract consecutive negative numbers?

### Intersection Sudoku 2

##### Age 11 to 16Challenge Level

A Sudoku with a twist.

### Simultaneous Equations Sudoku

##### Age 11 to 16Challenge Level

Solve the equations to identify the clue numbers in this Sudoku problem.

### Maths Trails

##### Age 7 to 14

The NRICH team are always looking for new ways to engage teachers and pupils in problem solving. Here we explain the thinking behind maths trails.

### Games Related to Nim

##### Age 5 to 16

This article for teachers describes several games, found on the site, all of which have a related structure that can be used to develop the skills of strategic planning.

### Colour Islands Sudoku

##### Age 11 to 14Challenge Level

An extra constraint means this Sudoku requires you to think in diagonals as well as horizontal and vertical lines and boxes of nine.

### Squares in Rectangles

##### Age 11 to 14Challenge Level

A 2 by 3 rectangle contains 8 squares and a 3 by 4 rectangle contains 20 squares. What size rectangle(s) contain(s) exactly 100 squares? Can you find them all?

### Window Frames

##### Age 5 to 14Challenge Level

This task encourages you to investigate the number of edging pieces and panes in different sized windows.

##### Age 11 to 14Challenge Level

You need to find the values of the stars before you can apply normal Sudoku rules.

### Cuboids

##### Age 11 to 14Challenge Level

Can you find a cuboid that has a surface area of exactly 100 square units. Is there more than one? Can you find them all?

### Ratio Sudoku 2

##### Age 11 to 16Challenge Level

A Sudoku with clues as ratios.

### Magnetic Personality

##### Age 7 to 16Challenge Level

60 pieces and a challenge. What can you make and how many of the pieces can you use creating skeleton polyhedra?

### Colour in the Square

##### Age 7 to 16Challenge Level

Can you put the 25 coloured tiles into the 5 x 5 square so that no column, no row and no diagonal line have tiles of the same colour in them?

### Seasonal Twin Sudokus

##### Age 11 to 16Challenge Level

This pair of linked Sudokus matches letters with numbers and hides a seasonal greeting. Can you find it?

##### Age 11 to 14Challenge Level

Replace the letters with numbers to make the addition work out correctly. R E A D + T H I S = P A G E

### Ratio Sudoku 3

##### Age 11 to 16Challenge Level

A Sudoku with clues as ratios or fractions.

### Twinkle Twinkle

##### Age 7 to 14Challenge Level

A game for 2 people. Take turns placing a counter on the star. You win when you have completed a line of 3 in your colour.

### Diagonal Product Sudoku

##### Age 11 to 16Challenge Level

Given the products of diagonally opposite cells - can you complete this Sudoku?

### Twin Corresponding Sudokus II

##### Age 11 to 16Challenge Level

Two sudokus in one. Challenge yourself to make the necessary connections.

### Special Numbers

##### Age 11 to 14Challenge Level

My two digit number is special because adding the sum of its digits to the product of its digits gives me my original number. What could my number be?

### Ratio Sudoku 1

##### Age 11 to 16Challenge Level

A Sudoku with clues as ratios.

### Wallpaper Sudoku

##### Age 11 to 16Challenge Level

A Sudoku that uses transformations as supporting clues.

### Two and Two

##### Age 11 to 16Challenge Level

How many solutions can you find to this sum? Each of the different letters stands for a different number.

### Latin Lilies

##### Age 7 to 14Challenge Level

In this game you are challenged to gain more columns of lily pads than your opponent.

### Where Can We Visit?

##### Age 11 to 14Challenge Level

Charlie and Abi put a counter on 42. They wondered if they could visit all the other numbers on their 1-100 board, moving the counter using just these two operations: x2 and -5. What do you think?

##### Age 11 to 14Challenge Level

By selecting digits for an addition grid, what targets can you make?

### Gabriel's Problem

##### Age 11 to 14Challenge Level

Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?

### Sticky Numbers

##### Age 11 to 14Challenge Level

Can you arrange the numbers 1 to 17 in a row so that each adjacent pair adds up to a square number?

##### Age 11 to 14Challenge Level

If you take a three by three square on a 1-10 addition square and multiply the diagonally opposite numbers together, what is the difference between these products. Why?

##### Age 7 to 14Challenge Level

I added together some of my neighbours' house numbers. Can you explain the patterns I noticed?

### 9 Weights

##### Age 11 to 14Challenge Level

You have been given nine weights, one of which is slightly heavier than the rest. Can you work out which weight is heavier in just two weighings of the balance?

### Twin Corresponding Sudoku III

##### Age 11 to 16Challenge Level

Two sudokus in one. Challenge yourself to make the necessary connections.

### The Great Weights Puzzle

##### Age 14 to 16Challenge Level

You have twelve weights, one of which is different from the rest. Using just 3 weighings, can you identify which weight is the odd one out, and whether it is heavier or lighter than the rest?

### Charitable Pennies

##### Age 7 to 14Challenge Level

Investigate the different ways that fifteen schools could have given money in a charity fundraiser.

### Summing Consecutive Numbers

##### Age 11 to 14Challenge Level

15 = 7 + 8 and 10 = 1 + 2 + 3 + 4. Can you say which numbers can be expressed as the sum of two or more consecutive integers?

##### Age 11 to 16Challenge Level

Four small numbers give the clue to the contents of the four surrounding cells.

##### Age 11 to 14Challenge Level

Rather than using the numbers 1-9, this sudoku uses the nine different letters used to make the words "Advent Calendar".

### Magic W

##### Age 14 to 16Challenge Level

Find all the ways of placing the numbers 1 to 9 on a W shape, with 3 numbers on each leg, so that each set of 3 numbers has the same total.

### Twin Line-swapping Sudoku

##### Age 14 to 16Challenge Level

A pair of Sudoku puzzles that together lead to a complete solution.

### Smith and Jones

##### Age 14 to 16Challenge Level

Mr Smith and Mr Jones are two maths teachers. By asking questions, the answers to which may be right or wrong, Mr Jones is able to find the number of the house Mr Smith lives in... Or not!

### Star Product Sudoku

##### Age 11 to 16Challenge Level

The puzzle can be solved by finding the values of the unknown digits (all indicated by asterisks) in the squares of the $9\times9$ grid.

### Peaches Today, Peaches Tomorrow...

##### Age 11 to 14Challenge Level

A monkey with peaches, keeps a fraction of them each day, gives the rest away, and then eats one. How long can his peaches last?

### I've Submitted a Solution - What Next?

##### Age 5 to 18

In this article, the NRICH team describe the process of selecting solutions for publication on the site.

### Advent Calendar 2011 - Secondary

##### Age 11 to 18Challenge Level

Advent Calendar 2011 - a mathematical activity for each day during the run-up to Christmas.

### A Long Time at the Till

##### Age 14 to 18Challenge Level

Try to solve this very difficult problem and then study our two suggested solutions. How would you use your knowledge to try to solve variants on the original problem?

### LCM Sudoku II

##### Age 11 to 18Challenge Level

You are given the Lowest Common Multiples of sets of digits. Find the digits and then solve the Sudoku.