3.49+12.4+6.66 4.6+3.3-4.4+6.7 37.12-19.78-2.22
24.75-4.96-6.75 12.64-(2.75+7.64) 12.8-(2.8+4.67)-5.33
5.26+7+1.74 27.85-(7.85+3.9)
5.6+2.7-3.6 10-2.75-3.25
15.25-3.1+0.65-4.9
27.3+73.2+72.7 43.25- 10.4-3.25
5.85-(1.89+1.85) 14.37-(7.42-4.37)
64.3-18.75+15.7-11.25
①74×78+26×78
②101×99
③43.51+20.4+56.49+9.6
①3.6﹣2.8+7.4﹣7.2
②1.25×1.6×25
③÷4
④÷[(﹣)×]