Working systematically

There are 549 NRICH Mathematical resources connected to Working systematically
Mixed-up Socks
problem

Mixed-up Socks

Age
5 to 7
Challenge level
filled star filled star empty star
Start with three pairs of socks. Now mix them up so that no mismatched pair is the same as another mismatched pair. Is there more than one way to do it?
Three by Three
problem

Three by Three

Age
5 to 11
Challenge level
filled star filled star empty star
Arrange 3 red, 3 blue and 3 yellow counters into a three-by-three square grid, so that there is only one of each colour in every row and every column
Whose Face?
problem

Whose Face?

Age
5 to 11
Challenge level
filled star empty star empty star
These are the faces of Will, Lil, Bill, Phil and Jill. Use the clues to work out which name goes with each face.
Snakes
problem

Snakes

Age
5 to 7
Challenge level
filled star filled star empty star
Explore the different snakes that can be made using 5 cubes.
6 Beads
problem

6 Beads

Age
5 to 7
Challenge level
filled star filled star empty star
If you put three beads onto a tens/ones abacus you can make the numbers 3, 30, 12 or 21. What numbers can be made with six beads?
Two Dice
problem

Two Dice

Age
5 to 7
Challenge level
filled star empty star empty star
Find all the numbers that can be made by adding the dots on two dice.
Red Express Train
problem

Red Express Train

Age
5 to 7
Challenge level
filled star empty star empty star
The Red Express Train usually has five red carriages. How many ways can you find to add two blue carriages?
Ladybird Box
problem

Ladybird Box

Age
5 to 11
Challenge level
filled star filled star empty star
Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.
Five Coins
problem

Five Coins

Age
5 to 11
Challenge level
filled star filled star empty star
Ben has five coins in his pocket. How much money might he have?
Four Triangles Puzzle
problem

Four Triangles Puzzle

Age
5 to 11
Challenge level
filled star empty star empty star
Cut four triangles from a square as shown in the picture. How many different shapes can you make by fitting the four triangles back together?