. Practical mathematics : an elementary treatise covering the fundamental processes of arithmetic, algebra, and geometry, with a practical presentation of logarithms and curve plotting. ound on B. If, however, 6 on B isbrought into coincidence with (IS) on A, it will befound that 2 on B is beyond the limits of A. Therefore,proceed as follows: With 6 on B coinciding with onA, set the runner so that the hair is oA*er the right in-dex of B. Xow push the slide to the right until theleft index comes under the hair. Then under 2 on B,the reading 6 will be found on A. 6 is, therefore, thefour
. Practical mathematics : an elementary treatise covering the fundamental processes of arithmetic, algebra, and geometry, with a practical presentation of logarithms and curve plotting. ound on B. If, however, 6 on B isbrought into coincidence with (IS) on A, it will befound that 2 on B is beyond the limits of A. Therefore,proceed as follows: With 6 on B coinciding with onA, set the runner so that the hair is oA*er the right in-dex of B. Xow push the slide to the right until theleft index comes under the hair. Then under 2 on B,the reading 6 will be found on A. 6 is, therefore, thefourth or unknown term of the proportion. In solvingexamples such as this, the slide may, of course, bemoved to the right or to the left, as may be requiredaccording to the numbers involved. Multiplication. Rule. Move the slide sotlint the index on the B scale coincides with themultiplicand on the A scale; then the product can(>< read on the .1 scale under the multiplier on theB scale. If preferred, the slide may be movedso that the index on the B scale coincides withthe multiplier on the A scale; then the productcan be read on the A scale under the multiplicandon the B 166 PRACTICAL MATHEMATICS Examples. 1. Multiply 25 by 15. Solution. Move the slide until the left index of B is over on under on B, will be found on A. The desired product is, there-fore, :>7f>, as it is clear by an inspection of the problem that the product mustcontain three digits. 2. Multiply 361 by 119. Solution. Move the slide so that the index on B is over on on B, read on A. It may be seen by inspection that the prod-uct will have five numerical places. The answer is, therefore, 42,900 approxi-mately. In large numbers, such as those used in this example, approximateresults only can be obtained, but they are sufficiently accurate for all practicalpurposes. Division. Rule. Move the slide so that the divisor on the Bscale will coincide with the divid
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmathematics, bookyear
