Skip to main content
### Number and algebra

### Geometry and measure

### Probability and statistics

### Working mathematically

### For younger learners

### Advanced mathematics

# The Value of Working Systematically

### How Old Am I?

### Odds and Evens Made Fair

### Sorted

### A Long Time at the Till

## You may also like

### Patterns in Number Sequences

### Reasoning Geometrically

### Reasoning with Numbers

Links to the University of Cambridge website
Links to the NRICH website Home page

Nurturing young mathematicians: teacher webinars

30 April (Primary), 1 May (Secondary)

30 April (Primary), 1 May (Secondary)

Or search by topic

Mathematicians often talk about the importance of working systematically on a problem, rather than approaching it in a random, unstructured way. The tasks in this feature have been chosen because systematic approaches will offer the most efficient routes to the solutions.

Age 14 to 16

Challenge Level

In 15 years' time my age will be the square of my age 15 years ago. Can you work out my age, and when I had other special birthdays?

Age 14 to 16

Challenge Level

In this follow-up to the problem Odds and Evens, we invite you to analyse a probability situation in order to find the general solution for a fair game.

Age 14 to 18

Challenge Level

How can you quickly sort a suit of cards in order from Ace to King?

Age 14 to 18

Challenge 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?

These resources are designed to get you thinking about number sequences and patterns.

These resources are designed to get you thinking about geometrical reasoning.

These resources are designed to get you thinking about reasoning with numbers.