①50× = ② × = ③12.4× = ④( )×35=
⑤ = ⑥9 = ⑦ = ⑧ =
÷= ×= 12×= + ×=
÷= ÷= 0×= =
× = × ÷ × = ÷ =
8÷ = × = ×16=
( + )×72= × ÷ = 12÷ = ÷ =
÷3= ×15= 1+2%= + × =
2﹣ = ×75%= ×4× = ×9÷ ×9=
正确计算:
错误的原因:
避免错误的方法:
=1×24
=24
解: (45%+30%) x=4.5
75%x=4.5
x=0.06
正确计算:45%+30%x=4.5
145+398= 6-0.6= 0.24×50= 3﹣3÷7= (+)×56=
1.25×6×8= = = ÷0.75= ×4÷×4=
480÷60= 3.72+6.28= +×1=
235+99= ﹣= 12×÷12×=
0.5÷5%= 0.75× = 2+3%= 3a×4a=