• 1. (2024一下·万载期末) 口算。

  20+50=	85-40=	27+8=	20+67=
  52-8=	7+31=	60-20=	90-6=
  36-(16-10)=	80-10-30=	44-9-20=
  10+55+8=	61-5+20=	73-(25+5)=