+ = 4× = - = ÷ = × =
2- = ÷ = × = ×0= ÷ =
+=
-=
1+=
1--=
我的思考过程:
综合算式:
307﹣299= += ×0.63= A﹣A=
5.2﹣0.6= ÷= ×= 4.25×4=