拡かく張ちょう倍ばい精せい度ど

• 倍ばい精せい度ど

  倍精度 is standard double-precision (64-bit), while 拡張倍精度 is an extended format with even higher precision.

• 単たん精せい度ど

  単精度 is single-precision (32-bit), a lower-precision format compared to 拡張倍精度.

Compound of 拡張 (extension) + 倍精度 (double-precision), a calque from English 'extended double-precision'.