Q:
# Who invented the adding machine?

A:

**The adding machine was invented by French mathematician, physicist and philosopher Blaise Pascal.** Pascal developed his mechanical device, which he named the Pascaline, in 1642. The apparatus, whose predecessor was the abacus, is regarded as the original digital calculator in that it operated by counting integers.

In 1671, the German mathematician and philosopher Gottfried Wilhem von Leibniz expanded on its design, resulting in the Step Reckoner, a calculating machine first built in 1673. The Step Reckoner could multiply as well as add by using repeated addition and shifting.

The first modern computer, the Analytical Engine, was not conceived until several years later in 1834 by English mathematician and mechanical engineer Charles Babbage.

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Q:
## How do you calculate exponential growth and decay?

A:Exponential growth and decay can be determined with the following equation: N = (NI)(e^kt). In this equation, "N" refers to the final population, "NI" is the starting population, "t" is the time over which the growth or decay took place and the "k" represents the growth or decay constant. If necessary, this equation may be rearranged to find any of these variables.

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Q:
## How much is 2 quarters, 4 dimes, 2 nickels and 1 penny?

A:If someone has 2 quarters, 4 dimes, 2 nickels and 1 penny, they have a total of $1.01. Every coin has a designated value. When counting money, one simply has to add these values together. Money is measured in cents. One dollar is equivalent to 100 cents.

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Q:
## How do I work out percentages on a calculator?

A:

Full Answer >**To determine a percentage, divide the actual number by the total possible number, and multiply the result by 100.**For example, if four out of five doctors agree on something, enter the equation in a calculator as "4 ÷ 5 x 100." The result, 80, is the percentage.Filed Under: -
Q:
## How do I calculate the upper or lower quartile?

A:

Full Answer >**To find the first quartile of a set of numbers, find the median of the lowest half of the data set.**This median is the first, or lowest, quartile in the data set. To find the third, or upper, quartile of a data set, instead find the median of the higher half of numbers in the set.Filed Under: