SIMON SINGH, FERMAT'S ENIGMA - India and Arabia... replaced the... Greek symbols and... Roman numerals with the counting system that has now been universally adopted. ... Try multiplying CLV by DCI and you will appreciate the significance of the breakthrough.

A. | Computer whose heyday has passed (2 wds.) | SLIDERULE |

B. | What a lemniscate represents | INFINITY |

C. | Geometrical curiosity seen in the art of M. C. Escher (2 wds.) | MOBIUSSTRIP |

D. | Tile total in a Scrabble set (2 wds.) | ONEHUNDRED |

E. | Movement in pedagogy mocked by Tom Lehrer (2 wds.) | NEWMATH |

F. | Character penny-wise but pound-foolish? | SHYLOCK |

G. | With H., proponent of the equation F = ma (2 wds.) | ISAAC |

H. | See G. | NEWTON |

I. | Pictorially plotted | GRAPHED |

J. | Progress; clearance | HEADWAY |

K. | Apologue | FABLE |

L. | Like the Ahmes arithmetic scroll in the British Museum | EGYPTIAN |

M. | Illegitimate act of subtraction? | ROBBERY |

N. | Typical tabletop brainteaser pieces | MATCHSTICKS |

O. | Instructive maxim | APOTHEGM |

P. | Student gone AWOL | TRUANT |

Q. | Octet + sestet | SONNET |

R. | Ovate; concise; cryptic | ELLIPTICAL |

S. | Behaving badly; a bit risque | NAUGHTY |

T. | The deriving of general truths from specific facts | INDUCTION |

U. | Where many dates may be observed | GRAVEYARD |

V. | Ductile; pliant; easily influenced | MALLEABLE |

W. | Stored in a repository, as documents or computer files | ARCHIVED |

This acrostic © 2006, The New York Times. XWord Info © 2007-2021, Jim Horne.