( )
637×5=
7×903=
8×52=
5×364=
199×7=
6×524=
86+45=
43-17=
370+130=
284+455=
1980-72÷9=
90-27=
3×8+74=
(436-388)÷8=
490+370=
760-240=
540+310=
840-270=
2.3+3.5= 6×2.5= += 1=
-= 12.6﹣2.6= 200﹣102= 0÷0.5=
= =0.25×0.4= 12.6÷0.2=