enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Mental calculation - Wikipedia

    en.wikipedia.org/wiki/Mental_calculation

    Mental calculation consists of arithmetical calculations using only the human brain, with no help from any supplies (such as pencil and paper) or devices such as a calculator. People may use mental calculation when computing tools are not available, when it is faster than other means of calculation (such as conventional educational institution ...

  3. Magic number (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Magic_number_(chemistry)

    The concept of magic numbers in the field of chemistry refers to a specific property (such as stability) for only certain representatives among a distribution of structures. It was first recognized by inspecting the intensity of mass-spectrometric signals of rare gas cluster ions. [ 1 ]

  4. Turnover number - Wikipedia

    en.wikipedia.org/wiki/Turnover_number

    In chemistry, the term "turnover number" has two distinct meanings. In enzymology , the turnover number ( k cat ) is defined as the limiting number of chemical conversions of substrate molecules per second that a single active site will execute for a given enzyme concentration [ E T ] for enzymes with two or more active sites. [ 1 ]

  5. Trachtenberg system - Wikipedia

    en.wikipedia.org/wiki/Trachtenberg_system

    The Trachtenberg system is a system of rapid mental calculation. The system consists of a number of readily memorized operations that allow one to perform arithmetic computations very quickly. It was developed by the Russian engineer Jakow Trachtenberg in order to keep his mind occupied while being a prisoner in a Nazi concentration camp.

  6. Scott Flansburg - Wikipedia

    en.wikipedia.org/wiki/Scott_Flansburg

    Scott Flansburg developed a mental math program called 'The Human Calculator. [9] ' Scott's course provides a step-by-step guide to becoming 'A Human Calculator.' Scott created this course to help people master mental mathematics. The training covers the unknown and hidden patterns behind numbers and how they work in our daily life.

  7. Mental calculator - Wikipedia

    en.wikipedia.org/wiki/Mental_calculator

    A mental calculator or human calculator is a person with a prodigious ability in some area of mental calculation (such as adding, subtracting, multiplying or dividing large numbers). In 2005, a group of researchers led by Michael W. O'Boyle, an American psychologist previously working in Australia and now at Texas Tech University , has used MRI ...

  8. Disproportionation - Wikipedia

    en.wikipedia.org/wiki/Disproportionation

    In the products, the chlorine in the Cl − ion has an oxidation number of −1, having been reduced, whereas the oxidation number of the chlorine in the ClO − 3 ion is +5, indicating that it has been oxidized. Decomposition of numerous interhalogen compounds involve disproportionation.

  9. Mental abacus - Wikipedia

    en.wikipedia.org/wiki/Mental_abacus

    Mental calculation is said to improve mental capability, increases speed of response, memory power, and concentration power. Many veteran and prolific abacus users in China, Japan, South Korea, and others who use the abacus daily, naturally tend to not use the abacus any more, but perform calculations by visualizing the abacus.