34×30= 340×600= 34×120=
4×0.25= 6.2-4.1= 5.7+4.3= 1-0.7=
0.4×0.01= 4.875+1.125= 0.3×2.1= 2.4×0.1=
15.4×10÷100= 28.6÷1000×100=
7+1 9-4 4+6 1+7 8-3 8-5 3+5 8-1
①
②
③1.25×88+12.5×1.2
④