(1)92+92×99
=92×1+92×99
=92×(99+1)
=92×100
=9200
(2)6.07+0.4-0.08
=6.07+0.4-(0.07+0.01)
=6.07+0.4-0.07-0.01
=6.07-0.07+0.4-0.01
=6+0.4-0.01
=6.4-0.01
=6.39
(3)8.2-9.6x0.5
=8.2-4.8
=3.4
(4)35x62+70x19
=35x62+35x2x19
=35x62+35x38
=35×(62+38)
=100×35
=3500
(5)24.6-3.98+5.4-6.02
=(24.6+5.4)-(3.98+6.02)
=30-10
=20
答:四年级脱式计算题如下:
38十47十62
=38十62十47
=100十47
=147。
203x5
=(200十3)x5
=200X5十15
二1000十15
=1015。
32X25x125
=4Ⅹ8x25x125
=(25x4)x(125x8)
=100X1000
=100000。
210÷(370一300)
=210÷70
=3。
…