Live Problems - Stage 4 & 5

Each time you visit the NRICH site there will be some activities which are 'live'. That means we are inviting you to send us your solutions and we will publish a selection of them, along with your name and school. If you'd like to read more about what we're looking for, read this short article.

Stage 4 & 5 Toughnutslive

Stage: 5 Challenge Level: Challenge Level:1

These Stage 4 and 5 problems haven't been solved yet. Can you be the first?

Hollow Squareslive

Stage: 4 Challenge Level: Challenge Level:1

Which armies can be arranged in hollow square fighting formations?

Difference of Two Squareslive

Stage: 4 Challenge Level: Challenge Level:2 Challenge Level:2

What is special about the difference between squares of numbers adjacent to multiples of three?

Pythagoras Perimeterslive

Stage: 4 Challenge Level: Challenge Level:2 Challenge Level:2

If you know the perimeter of a right angled triangle, what can you say about the area?

Mega Quadratic Equationslive

Stage: 5 Challenge Level: Challenge Level:1

What do you get when you raise a quadratic to the power of a quadratic?

System Speaklive

Stage: 5 Challenge Level: Challenge Level:1

Five equations... five unknowns... can you solve the system?