503+497 =
62+38×0=
52+25-52+25=
0.6÷100=
1 . 36×1000 =
28÷4×7=
174-48-52=
5×4÷5×4=
42 - 42÷42 =
10.1+0.9=
6.86-1.6=
+10.3=
0.05×1000=
421÷69≈
9.6+0×6.4-6.4=
①0.53×2.5+
②25×0.032×12.5
③ [()×]
④6.83+17.9﹣0.83+32.1