A system for doing multiplication and addition quickly through the use of mental qtricks.q... Trachtenberg system will prove an excellent springboard in mastering the many other ingenious and original devices that ... And you will learn a unique theory of checking your answers which will give you an assurance of accuracy achievedanbsp;...

Title | : | Instant Math, Based on the Trachtenberg Speed System of Basic Mathematics |

Author | : | Ann Cutler |

Publisher | : | - 1962 |

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