Correction to final square: 2^63 not 2^64 grains of rice

by R J Hunter
(Nyssa, Oregon, USA)

On the first square there is one grain of rice which is 2 to the power 0, not 2 to the power 1. So the number of grains on any nth square 2 to the power (n-1), and on the 64th square 2 to the 63rd which is 9 with 18 zeros. If you total the rice on all 64 squares then it comes to the 18,000,000,000,000,000,000 stated.