10-digit desktop calculator is made from the recycled materials of Canon copiers with the upper and lower casings being made with a high percentage of recycled material. Functions include tax calculation, square root, sign change, three-key memory, multiplication, division, percentage calculations and grand total. Decimal positions include A, 4, 3, 2, 0, and F. The large LCD screen easily shows all your computations. Desktop calculator runs on solar and battery power and shuts off automatically after approximately seven minutes.