(1) ÷ = | (2)0.25× = | (3)1.8× = | (4) ÷0.125= |
(5) ×3= | (6) × = | (7) × = | (8) ÷3= |
(9) ÷25%= | (10) +0.5%= | (11)20%×40%= | (12)78%-0.5= |
(13) ×(1+ )= | (14) ×6- = | (15) × + × = | (16) × ÷ × = |
解:
(1) ÷ = , | (2)0.25× = , | (3)1.8× =0.4, | (4) ÷0.125=5, |
(5) ×3= , | (6) × = , | (7) × = , | (8) ÷3= , |
(9) ÷25%=1, | (10) +0.5%=0.505, | (11)20%×40%=0.08, | (12)78%-0.5=0.28, |
(13) ×(1+ )= , | (14) ×6- = , | (15) × + × = , | (16) × ÷ × = . |
分析:分数乘法:分子相乘的积做分子,分母相乘的积做分母;
分数除法:除以一个数等于乘这个数的倒数.
(13)先算小括号里面的加法,再算括号外的乘法;
(14)(15)运用乘法分配律简算;
(16)按照从左到右的顺序计算.
点评:本题考查了简单的分数乘除法计算,计算时要细心,注意把结果化成最简分数.
÷
=
=
=
÷0.125=
×3=
=
×
=
÷3=
+0.5%=
×(1+
×6-
×
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