Calculate the number 787
NUMBERMANIA: Calculate the number 787 using numbers [4, 7, 4, 7, 10, 764] and basic arithmetic operations (+, -, *, /). Each of the numbers can be used only once.Correct answers: 3
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Pencil with eraserIn 1858, the first U.S. patent for a combination lead pencil and eraser was issued to Hyman L. Lipman, of Philadelphia, Pa. (No. 19,783). The pencil was made in the usual manner, with one-fourth of its length reserved inside one end to carry a piece of prepared india-rubber, glued in at one edge. Thus cutting one end prepared the lead for writing, while cutting the other end would expose a small piece of india rubber. This eraser was then conveniently available whenever needed, and not subject to being mislaid. Further, the eraser could be sharpened to a finer point to make a more precise erasure of fine lines in a drawing, or cut further down if the end became soiled. |