①
②
③
① - -
② -( + )
③ + -
④
⑤
⑥
①7.4﹣6.62+20.6﹣13.38
②×+×
③(-+)÷
④2×0.8×12.5×50%
⑤÷(÷+)
⑥×[1÷(+)]
①836-192÷8×16
②1.4÷(1.4+0.7)
③0.8×0.4×12.5×0.25
④ ÷6+ ÷20
⑤14×19×( + )
⑥ ÷[( + )÷ ]