A:(−13)2 =±13
B:114 =1× 14 =1 12
C:(1−3)2 = 3 ﹣1
D:52−42 = 52 ﹣ 42 =5﹣4=1
①26.7+147.2=
②801.6-21.9=
③20-0.85=
④15.78+2.45=
验算:
⑤33.4-9.48=
⑥13.1+120.95=
⑦100-19.2=