200+300÷5 12×68÷4 33×24-19
600÷3 =
840÷4 =
60×50 =
2.5-1.8=
20×23 =
20×42 =
4.7+3=
+=
5.6-3.9=
29+81=
4.8+2.5=
1-=
64000平方米=公顷 4.2升=毫升