分析:(1)(5)可根據(jù)加法交換律進行計算;
(2)(6)可根據(jù)一個數(shù)減兩個數(shù),等于用這個數(shù)減去這兩個數(shù)的和的減法性質(zhì)計算;
(3)可根據(jù)一個數(shù)減兩個數(shù)的和,等于用這個數(shù)分別、減去這兩個數(shù)的減法性質(zhì)計算;
(4)按從左到右的順序計算即可;
(5)可根據(jù)加法交換律計算.
解答:解:(1)4.32+5.43+6.68
=4.32+6.68+5.43,
=11+5.43,
=16.43;
(2)15.17-6.8-3.2
=15.17-(6.8+3.2),
=15.17-10,
=5.17;
(3)34.82-(4.82+15.2)
=34.82-4.82-15.2,
=30-15.2,
=14.8;
(4)15.27+4.72-5.28
=19.99-5.28,
=14.71;
(5)4.02-3.5+0.98
=4.02+0.98-3.5,
=5-3.5,
=1.5;
(6)5.8-4.5+5.8-4.5
=5.8+5.8-(4.5+4.5),
=11.6-9,
=2.6.
點評:完成本題要注意分析式中數(shù)據(jù)的特點,然后運用合適的方法進行計算.