《2025年口算训练五年级数学上册人教版双色升级版》

$50 × 0.87 × 2 =$
$125 × 0.56 × 8 =$
$4 × 0.45 × 25 =$
$1.25 × 0.8 × 5.5 =$
$0.25 × 3.2 × 40 =$
$101 × 2.5 =$
$0.4 × 6.18 × 0.25 =$
$0.8 × (1.25 × 16) =$
$(0.65 × 0.4) × 2.5 =$
$(5.3 + 2.7) × 0.6 =$
$(100 + 2) × 0.65 =$
$(100 - 1) × 0.65 =$
$6 × 0.68 + 0.32 × 6 =$
$50 × 0.41 × 0.2 =$
$2.5 × (0.77 × 0.4) =$
$125 × (0.7 × 0.8) =$
$4.7 + 99 × 4.7 =$
$(12.5 + 12.5) × 8 =$
$3.2 × 1.25 × 0.8 =$
$5 × 1.49 + 8.51 × 5 =$
$99 × 7.2 + 7.2 =$

答案： 解析：这些题目主要考查了小数的四则混合运算以及简便计算的方法，包括乘法交换律、结合律、分配律的应用。
$50 × 0.87 × 2$
$= 50 × 2 × 0.87$
$= 100 × 0.87$
$= 87$
$125 × 0.56 × 8$
$= 125 × 8 × 0.56$
$= 1000 × 0.56$
$= 560$
$4 × 0.45 × 25$
$= 4 × 25 × 0.45$
$= 100 × 0.45$
$= 45$
$1.25 × 0.8 × 5.5$
$= 1 × 5.5$
$= 5.5$
$0.25 × 3.2 × 40$
$= 0.25 × 40 × 3.2$
$= 10 × 3.2$
$= 32$
$101 × 2.5$
$=(100 + 1) × 2.5$
$= 100 × 2.5 + 1 × 2.5$
$= 250 + 2.5$
$= 252.5$
$0.4 × 6.18 × 0.25$
$= 0.4 × 0.25 × 6.18$
$= 0.1 × 6.18$
$= 0.618$
$0.8 × (1.25 × 16)$
$= 0.8 × 1.25 × 16$
$= 1 × 16$
$= 16$
$(0.65 × 0.4) × 2.5$
$= 0.65 × (0.4 × 2.5)$
$= 0.65 × 1$
$= 0.65$
$(5.3 + 2.7) × 0.6$
$= 8 × 0.6$
$= 4.8$
$(100 + 2) × 0.65$
$= 100 × 0.65 + 2 × 0.65$
$= 65 + 1.3$
$= 66.3$
$(100 - 1) × 0.65$
$= 100 × 0.65 - 1 × 0.65$
$= 65 - 0.65$
$= 64.35$
$6 × 0.68 + 0.32 × 6$
$= 6 × (0.68 + 0.32)$
$= 6 × 1$
$= 6$
$50 × 0.41 × 0.2$
$= 50 × 0.2 × 0.41$
$= 10 × 0.41$
$= 4.1$
$2.5 × (0.77 × 0.4)$
$= 2.5 × 0.4 × 0.77$
$= 1 × 0.77$
$= 0.77$
$125 × (0.7 × 0.8)$
$= 125 × 0.8 × 0.7$
$= 100 × 0.7$
$= 70$
$4.7 + 99 × 4.7$
$= 4.7 × (1 + 99)$
$= 4.7 × 100$
$= 470$
$(12.5 + 12.5) × 8$
$= 12.5 × 8 + 12.5 × 8$
$= 100 + 100$
$= 200$
$3.2 × 1.25 × 0.8$
$= 3.2 × (1.25 × 0.8)$
$= 3.2 × 1$
$= 3.2$
$5 × 1.49 + 8.51 × 5$
$= 5 × (1.49 + 8.51)$
$= 5 × 10$
$= 50$
$99 × 7.2 + 7.2$
$= 7.2 × (99 + 1)$
$= 7.2 × 100$
$= 720$

$195 + 515 + 225 =$935
$357 ÷ 7 × 20 =$1020
$6.2 × 0.8 × 10 =$49.6
$360 - 110 + 345 =$595
$891 + 102 + 129 =$1122
$455 × 2 + 9 =$919
$490 ÷ 70 + 70 =$77
$(561 - 121) ÷ 4 =$110
$48 + 32 - 17 =$63
$20 ÷ 4 × 123 =$615
$(90 - 39) ÷ 3 =$17
$2 × (650 - 470) =$360
$5 × 16 ÷ 400 =$0.2
$120 ÷ 2 × 25 =$1500
$24 ÷ 6 × 220 =$880
$430 × 3 + 30 × 6 =$1470
$(870 - 530) × 2 + 40 =$720
$401 × 2 + 119 × 2 =$1040
$703 + 127 + 97 =$927
$125 × 80 + 8 =$10008
$240 + 360 ÷ 6 =$300

答案： 解析：这些题目都是基础的数学运算题目，包括加法、减法、乘法、除法以及它们的组合。根据五年级的数学课程标准，学生应该已经掌握了这些基本的数学运算。
答案：
$195 + 515 + 225 = 935$
$357 ÷ 7 × 20 = 1020$
$6.2 × 0.8 × 10 = 49.6$
$360 - 110 + 345 = 595$
$891 + 102 + 129 = 1122$
$455 × 2 + 9 = 919$
$490 ÷ 70 + 70 = 77$
$(561 - 121) ÷ 4 = 110$
$48 + 32 - 17 = 63$
$20 ÷ 4 × 123 = 615$
$(90 - 39) ÷ 3 = 17$
$2 × (650 - 470) = 360$
$5 × 16 ÷ 400 = 0.2$
$120 ÷ 2 × 25 = 1500$
$24 ÷ 6 × 220 = 880$
$430 × 3 + 30 × 6 = 1470$
$(870 - 530) × 2 + 40 = 720$
$401 × 2 + 119 × 2 = 1040$
$703 + 127 + 97 = 927$
$125 × 80 + 8 = 10008$
$240 + 360 ÷ 6 = 300$