Children's Television Workshop proposes to produce a fourth and fifth season of SQUARE ONE TV, a daily series on mathematics for children ages eight to twelve. Season Four will consist of 40 new half-hours for air on PBS stations beginning September 1991. Consistent with CTW's experimental mission in education, CTW also proposes to undertake a new programming approach to expand the reach of SQUARE ONE TV to a family audience by converting the daily detective serial featured in the series, MATHNET, into four one-hour specials for family viewing. These Season Four MATHNET Specials will be researched to test their effectiveness. Eleven hour-long weekly SQUARE ONE TV programs will be produced for Season Five to be aired in addition to re-broadcasts of the daily series starting January, 1993. Seasons Four and Five production will capitalize on the educational impact and appeal of prior seasons. Mathematical content will be based on research and in conjunction with the Series Advisory Committee and consultants. The additional seasons will be supported by a full range of promotion, community outreach activities, and school services, including teacher's guides.