①-+ ②+(-) ③6÷5+
④-(7.5-) ⑤-+- ⑥0.25-+-
﹣+ ﹣(+) +﹣+ .
+- 3-- 0.25×0.4+0.25×0.4 ++++
12-5÷12- 1--
12.45+-3.45+ -(+)