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?

Irrational Arithmagonslive

Stage: 5 Challenge Level: Challenge Level:2 Challenge Level:2

Can you work out the irrational numbers that belong in the circles to make the multiplication arithmagon correct?

Fit for Photocopyinglive

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

Explore the relationships between different paper sizes.

The Root of the Problemlive

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

Find the sum of this series of surds.