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#### Resources tagged with Counting similar to Groups of Sets:

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### There are 11 results

Broad Topics > Numbers and the Number System > Counting

##### Stage: 1, 2, 3 and 4

Nowadays the calculator is very familiar to many of us. What did people do to save time working out more difficult problems before the calculator existed?

### Slippery Snail

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

A game for two people, who take turns to move the counters. The player to remove the last counter from the board wins.

### Binary Sequences

##### Stage: 5 Challenge Level:

Show that the infinite set of finite (or terminating) binary sequences can be written as an ordered list whereas the infinite set of all infinite binary sequences cannot.

### Diagonal Sums Sudoku

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

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

### Euler's Officers

##### Stage: 4 Challenge Level:

How many different ways can you arrange the officers in a square?

##### Stage: 4 Challenge Level:

Follow-up to the February Game Rules of FEMTO.

### Ruler

##### Stage: 5 Challenge Level:

The interval 0 - 1 is marked into halves, quarters, eighths ... etc. Vertical lines are drawn at these points, heights depending on positions. What happens as this process goes on indefinitely?

### FEMTO

##### Stage: 4 Challenge Level:

A new card game for two players.

##### Stage: 4 and 5

Some puzzles requiring no knowledge of knot theory, just a careful inspection of the patterns. A glimpse of the classification of knots, prime knots, crossing numbers and knot arithmetic.

### Doodles

##### Stage: 4 Challenge Level:

Draw a 'doodle' - a closed intersecting curve drawn without taking pencil from paper. What can you prove about the intersections?