Great problems on the Nrich Site
.
We would suggest that ...

Stage 3 is suitable for S1-S2

Stage 4 is suitable for S3-S4

Stage 5 is suitable for S5-S6

Also remember to try the unsolved Tough Nuts.

The Digits of the Year Challenge:

• 2009
• 2006
• 2005
• 2004
• 2003
• 2002
• 2001
• 2000 (The Great Millenial Challenge)
• 1999
• 1998
• History of the activity

The Loopy Number search:

• Introduction and diagrams
• The Loopy Number List

The Hole-in-One Records:

• Introduction
• The records: 2 3 4 5 6 7 8

Gridbugs:

• Welcome to the world of Gridbugs

Pi Records & Mnemonics:

• The Pi Memorising Record for UK Schools
• Pi mnemonics from our students