解题思路:①13.65+32.47+17.52,按照从左到右的顺序计算;
②78.14-31.43-18.57,根据减法的运算性质进行简算;
③143-15.28-84.72,根据减法的运算性质进行简算;
④53.27-8.4-3.27-1.6,根据减法的运算性质进行简算;
⑤(13.1-9.28)-(4.5-2.74),先算括号里面的,再算减法;
⑥56.65-(13.22+16.65),根据减法的运算性质进行简算;
①13.65+32.47+17.52
=46.12+17.52
=63.64;
②78.14-31.43-18.57
=78.14-(31.43+18.57)
=78.14-50
=28.14;
③143-15.28-84.72
=143-(15.28+84.72)
=143-100
=43;
④53.27-8.4-3.27-1.6
=53.27-3.27-(8.4+1.6)
=50-10
=40;
⑤(13.1-9.28)-(4.5-2.74)
=3.82-1.76
=2.06;
⑥56.65-(13.22+16.65)
=56.65-16.65-13.22
=40-13.22
=26.78.
点评:
本题考点: 小数四则混合运算;运算定律与简便运算.
考点点评: 此题考查的目的是理解掌握小数四则混合运算的顺序以及小数四则运算的计算法则,并且能否灵活选择简便方法进行简算.