(1) 94 × 8 = 752
(2) 57 × 6 = 342
(3) 9 ×67 =603
(4) 26×9=234
(5) 41 × 9 =369
(6) 57 × 3 =171
(7) 7 × 79 = 553
(8) 62 × 5 = 310
(9) 3 × 57 =171
(10) 5 × 84 = 420
(11) 8 × 26 =208
(12) 5 × 67 =335
(13) 37 × 4 = 148
(14) 8 × 98 =784
(15) 6 × 24 = 144
(16) 98 × 5 =490
(17) 12 × 2 =24
(18) 9 × 75 = 675
(20) 68 × 2 =136
答：四年级20个脱式计算如下：
103Ⅹ45
=（100十3）x45
=100Ⅹ45十3X45
=4500十135
=4635
99Ⅹ37十37
=37Ⅹ（99十1）
=37x100
=3700
32Ⅹ25X125
=4×8X25X125
=（25Ⅹ4）X（125Ⅹ8）
=100Ⅹ1000
=100000
25X200x4
=25X4乂200
=100Ⅹ200
=20000。
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