An Apparatus for Facilitating the Multiplication and Division of Whole Numbers and Decimals.

摘要

22,445. Gray, H. Sept. 28. Multiplying and dividing apparatus.-An apparatus for facilitating the multiplication and division of numbers, in which the multiples of the digits are marked in columns on a series of continuous bands mounted on rollers B and adapted to pass over strips A, is provided with an improved means for mounting the rollers, means to indicate the position of the decimal point, and a cursor to facilitate the reading of the apparatus. The rollers B, for convenience in handling, are arranged in two planes, every alternate roller being in the same plane, and their milled heads are adapted to be pulled out to enable the rollers to be rotated. The end strips are marked with the numbers 1 ... 9, and, to shut out the rows of numbers next the one under consideration, a cursor C is provided. The reading is taken from right to left, and the figures between the diagonal lines are added together. Above each strip is a hole D in the framework, into which a pointer E is inserted to indicate the decimal point.