①6.45-2.74+3.6
②45.36+(83.4-15.07)
③67.39-(12.67+17.39)
④4.5+3.8+15.5
⑤35.62-8.38-5.62
⑥2.06+5.42+3.94+2.58
436-156-44
=436-156+44
=280+44
=324
(两种方法解答)
方法一:
方法二: