Search by Topic

Resources tagged with Working systematically similar to Intersections:

Filter by: Content type:
Stage:
Challenge level: Challenge Level:1 Challenge Level:2 Challenge Level:3

There are 128 results

Broad Topics > Using, Applying and Reasoning about Mathematics > Working systematically

problem icon

Problem Solving, Using and Applying and Functional Mathematics

Stage: 1, 2, 3, 4 and 5 Challenge Level: Challenge Level:1

Problem solving is at the heart of the NRICH site. All the problems give learners opportunities to learn, develop or use mathematical concepts and skills. Read here for more information.

problem icon

All-variables Sudoku

Stage: 3, 4 and 5 Challenge Level: Challenge Level:1

The challenge is to find the values of the variables if you are to solve this Sudoku.

problem icon

Quadruple Clue Sudoku

Stage: 3 and 4 Challenge Level: Challenge Level:1

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.

problem icon

Another Quadruple Clue Sudoku

Stage: 3 and 4 Challenge Level: Challenge Level:1

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.

problem icon

Intersection Sudoku 2

Stage: 3 and 4 Challenge Level: Challenge Level:1

A Sudoku with a twist.

problem icon

Equation Sudoku

Stage: 3, 4 and 5 Challenge Level: Challenge Level:1

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

problem icon

Intersection Sudoku 1

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

A Sudoku with a twist.

problem icon

Addition Equation Sudoku

Stage: 3, 4 and 5 Challenge Level: Challenge Level:1

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

problem icon

LCM Sudoku II

Stage: 3, 4 and 5 Challenge Level: Challenge Level:1

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

problem icon

Advent Calendar 2011 - Secondary

Stage: 3, 4 and 5 Challenge Level: Challenge Level:1

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

problem icon

Spot the Card

Stage: 4 Challenge Level: Challenge Level:1

It is possible to identify a particular card out of a pack of 15 with the use of some mathematical reasoning. What is this reasoning and can it be applied to other numbers of cards?

problem icon

One Out One Under

Stage: 4 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Imagine a stack of numbered cards with one on top. Discard the top, put the next card to the bottom and repeat continuously. Can you predict the last card?

problem icon

The Great Weights Puzzle

Stage: 4 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

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?

problem icon

Introducing NRICH TWILGO

Stage: 1, 2, 3, 4 and 5 Challenge Level: Challenge Level:1

We're excited about this new program for drawing beautiful mathematical designs. Can you work out how we made our first few pictures and, even better, share your most elegant solutions with us?

problem icon

Games Related to Nim

Stage: 1, 2, 3 and 4

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.

problem icon

Magic Caterpillars

Stage: 4 and 5 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Label the joints and legs of these graph theory caterpillars so that the vertex sums are all equal.

problem icon

Plum Tree

Stage: 4 and 5 Challenge Level: Challenge Level:1

Label this plum tree graph to make it totally magic!

problem icon

Corresponding Sudokus

Stage: 3, 4 and 5

This second Sudoku article discusses "Corresponding Sudokus" which are pairs of Sudokus with terms that can be matched using a substitution rule.

problem icon

Latin Squares

Stage: 3, 4 and 5

A Latin square of order n is an array of n symbols in which each symbol occurs exactly once in each row and exactly once in each column.

problem icon

Twin Corresponding Sudokus II

Stage: 3 and 4 Challenge Level: Challenge Level:1

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

problem icon

Colour in the Square

Stage: 2, 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

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?

problem icon

Constellation Sudoku

Stage: 4 and 5 Challenge Level: Challenge Level:2 Challenge Level:2

Special clue numbers related to the difference between numbers in two adjacent cells and values of the stars in the "constellation" make this a doubly interesting problem.

problem icon

Pole Star Sudoku 2

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

This Sudoku, based on differences. Using the one clue number can you find the solution?

problem icon

LOGO Challenge - Triangles-squares-stars

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

Can you recreate these designs? What are the basic units? What movement is required between each unit? Some elegant use of procedures will help - variables not essential.

problem icon

Wallpaper Sudoku

Stage: 3 and 4 Challenge Level: Challenge Level:1

A Sudoku that uses transformations as supporting clues.

problem icon

Ratio Sudoku 1

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

A Sudoku with clues as ratios.

problem icon

Quadruple Sudoku

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

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

problem icon

Integrated Product Sudoku

Stage: 3 and 4 Challenge Level: Challenge Level:1

This Sudoku puzzle can be solved with the help of small clue-numbers on the border lines between pairs of neighbouring squares of the grid.

problem icon

Magnetic Personality

Stage: 2, 3 and 4 Challenge Level: Challenge Level:1

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

problem icon

LOGO Challenge - the Logic of LOGO

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

Just four procedures were used to produce a design. How was it done? Can you be systematic and elegant so that someone can follow your logic?

problem icon

Seasonal Twin Sudokus

Stage: 3 and 4 Challenge Level: Challenge Level:1

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

problem icon

Cinema Problem

Stage: 3 and 4 Challenge Level: Challenge Level:1

A cinema has 100 seats. Show how it is possible to sell exactly 100 tickets and take exactly £100 if the prices are £10 for adults, 50p for pensioners and 10p for children.

problem icon

Integrated Sums Sudoku

Stage: 3 and 4 Challenge Level: Challenge Level:1

The puzzle can be solved with the help of small clue-numbers which are either placed on the border lines between selected pairs of neighbouring squares of the grid or placed after slash marks on. . . .

problem icon

Ratio Sudoku 3

Stage: 3 and 4 Challenge Level: Challenge Level:1

A Sudoku with clues as ratios or fractions.

problem icon

Ratio Sudoku 2

Stage: 3 and 4 Challenge Level: Challenge Level:1

A Sudoku with clues as ratios.

problem icon

LOGO Challenge - Pentagram Pylons

Stage: 3, 4 and 5 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Pentagram Pylons - can you elegantly recreate them? Or, the European flag in LOGO - what poses the greater problem?

problem icon

Pole Star Sudoku

Stage: 4 and 5 Challenge Level: Challenge Level:1

A Sudoku based on clues that give the differences between adjacent cells.

problem icon

Rainstorm Sudoku

Stage: 4 Challenge Level: Challenge Level:1

Use the clues about the shaded areas to help solve this sudoku

problem icon

Rectangle Outline Sudoku

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

Each of the main diagonals of this sudoku must contain the numbers 1 to 9 and each rectangle width the numbers 1 to 4.

problem icon

Twin Corresponding Sudoku III

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

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

problem icon

Twin Chute-swapping Sudoku

Stage: 4 and 5 Challenge Level: Challenge Level:1

A pair of Sudokus with lots in common. In fact they are the same problem but rearranged. Can you find how they relate to solve them both?

problem icon

Twin Corresponding Sudoku

Stage: 3, 4 and 5 Challenge Level: Challenge Level:1

This sudoku requires you to have "double vision" - two Sudoku's for the price of one

problem icon

I've Submitted a Solution - What Next?

Stage: 1, 2, 3, 4 and 5

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

problem icon

Alphabetti Sudoku

Stage: 3 and 4 Challenge Level: Challenge Level:1

This Sudoku requires you to do some working backwards before working forwards.

problem icon

Sandwiches

Stage: 2, 3, 4 and 5 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Arrange the digits 1, 1, 2, 2, 3 and 3 so that between the two 1's there is one digit, between the two 2's there are two digits, and between the two 3's there are three digits.

problem icon

The Naked Pair in Sudoku

Stage: 2, 3 and 4

A particular technique for solving Sudoku puzzles, known as "naked pair", is explained in this easy-to-read article.

problem icon

A Long Time at the Till

Stage: 4 and 5 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

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?

problem icon

Diagonal Sums Sudoku

Stage: 2, 3 and 4 Challenge Level: Challenge Level:1

Solve this Sudoku puzzle whose clues are in the form of sums of the numbers which should appear in diagonal opposite cells.

problem icon

Multiplication Equation Sudoku

Stage: 4 and 5 Challenge Level: Challenge Level:2 Challenge Level:2

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.

problem icon

Olympic Logic

Stage: 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

Can you use your powers of logic and deduction to work out the missing information in these sporty situations?