How much does a social worker make? According to the May 2012 records from the Bureau of Labor Statistics, the mean annual healthcare social worker salary is $51,460, or $24.74 per hour. The lowest ten percent earn $31,410, while the top ten percent make an average of $74,030 annually.
The Leibniz Step Reckoner. Gottfried Leibnizâs 1673 âStep Reckonerâ introduced a design innovation that enabled a single gear to represent any digit from 0 to 9 in just one revolution. This stepped-drum approach dominated calculator design for the next two centuries. Gottfried Leibniz.
A replica of the Stepped Reckoner of Leibniz form 1923 (original is in the Hannover Landesbibliothek) The mechanism of the machine is 67 cm long, 27 wide and 17 cm high and is housed in a big oak case with dimensions 97/30/25 cm. Let's examine what is the principle of the stepped-drum (see the lower sketch).