能简算的就简算．
①2.983+0.53+1.25         ②23.75﹣3.625﹣0.375        ③5.1+0.9﹣5.1+0.9
④49.3﹣28.5+20.5         ⑤6.32﹣（5.26﹣3.52）       ⑥10.75+0.4+0.25．