=
= =
= =
=
①
②
③
④
⑤
⑥54.3×1.8+54.3×0.3﹣54.3×0.1
① + +
② - -
③ - +
④ - - +
⑤ +( + )
⑥ -( - )
+ = + = 4÷9=
- = 2- = + + + =
+ = - = + = - = - + =
5- = +0.2= + = -0.125= - - =
① -( - )
② - -
③ + + +
④ - +
⑤ -( + )
⑥ -( + )
①
②
③
④
⑤
⑥