① ②
③ ④
1998×(-)+11×(-)-2009×(+)+3
① + + +
② × + ÷
③3.8×9.9+0.38
④(8+ )÷4
⑤6÷ + ÷6
⑥ ÷[( + )× ]
28.7﹣(18.7﹣6.2)
3.68×[1÷(2 ﹣2.09)]
①
②
③
④
①÷×
②×3.2+6.8÷
③105×(+)
④﹣+﹣
⑤6.4÷[(3﹣1.4)×]
①21×16÷14+76
②9- -
③ ×0.8×12.5
④48×( + - )
⑤7.6×9.4- +7.6×1.6
⑥ ×[ ÷(0.4- )]