World's Smallest Hello Kitty® Calculator Celebrate the 45th anniversary of the original Hello Kitty® Calculator from 1976 in miniature size! Say goodbye to your basic grey calculator and head back to school or the office in retro style! This miniature calculator is sure to make you smile! World's Smallest Hello Kitty® Calculator measures 25x.25×2.75inches. Slide the Hello Kitty® head up to turn on and slide down to turn off. Non-replaceable battery included. Available in two colors – red and blue.