A wonderful piece of mid-century American ingenuity — the Ken-Add “Convenient Purse Size Adding Machine” by Ken-Add Machines Co. of St. Paul, Minnesota. The sleek diamond-knurled aluminum case snaps open to reveal a green enameled dial-wheel interior with four columns for dollars and cents, capable of totaling up to $9,999. Original instruction card still in place inside the lid. Marked “Pat. Applied For.” Approximately 5” long. 5.5 oz