Question

3．計算下面各題，能簡便的就簡便計算．

0.713×0.25×4	5.5×8-4.5÷0.125	7.2÷6.4
0.76×101	5.29×73+52.9×2.7	1.6÷0.3+4.4÷0.3

Answer 1

分析 ①運用乘法結合律簡算，
②先算乘法和除法，再算減法，
③先把6.4變成0.8×8，再根據(jù)除法的性質簡算，
④先把101變成100+1，再用乘法分配律簡算，
⑤先把5.29×73變成52.9×7.3，再逆用乘法分配律簡算，
⑥根據(jù)除法的性質簡算．

解答 解：①0.713×0.25×4 
=0.713×（0.25×4）
=0.713×1
=0.713  

②5.5×8-4.5÷0.125  
=44-36
=8         

③7.2÷6.4
=7.2÷（0.8×8）
=7.2÷0.8÷8
=9÷8
=1.125

④0.76×101 
=0.76×（100+1）
=0.76×100+0.76×1
=76+0.76
=76.76            

⑤5.29×73+52.9×2.7  
=52.9×7.3+52.9×2.7
=52.9×（7.3+2.7）
=52.9×10
=529 

⑥1.6÷0.3+4.4÷0.3
=（1.6+4.4）÷0.3
=6÷0.3
=20

點評 此題考查小數(shù)四則混合運算順序和靈活運用運算定律，分析數(shù)據(jù)找到正確的計算方法．