=   =   =   =
=   =   =   =
=   =   =   =
=   =   =   =
=   =   =   =
=    2.5×16=   =   =
=   =   =   =
=    1.5÷0.05=   =    1.5÷0.05=
=   =   =    2.5×0.4=
=   =   =   =
=   =   =   =
=   =   =    6.25+1.75=
=   =   =   =
=   =   =   =
=   =   =   =
=   =