This issue has plenty of material on prime numbers, and the cover depicts, amidst a generous sprinkling of primes, the famous Greek mathematician Eratosthenes who made important contributions to Mathematics and Geography. Art and Mathematics section features some incredible ambigrams by Punya Misra and Gaurav Bhatnagar and the math behind them. A Teacher’s Diary on Classroom Assessment which is a joint effort of the A&P and IAA teams and is an attempt to translate the vision of CCE into practice. ‘How to Prove It’ which presents through case studies-themes, approaches and strategies connected with proof. The pullout this time focuses on subtraction.