计算（简便计算、用四年级的）判断：102x56 改正：864-299=100x56+2 =864-300-1=5600+2 =564-1=5602 （x或√） =563 （x或√） 简便计算：25x24= 125x32= 540|2|27= 8900|25|4= 2000|8|125= 99x36+36= 735-208= 243-95= 245-125+355-175=注：|=除号

1. 错
102x56
=100x56+2x56
=5600+112
=5712
864-299
=864-(300-1)
=864-300+1
=564+1
=565
25x24=25x4x6=100x6=600

125x32=125x4x8=1000x8=8000
540|2|27=540/27/2=20/2=10
8900|25|4=8900/(25*4)=8900/100=89
2000|8|125=2000/(8*125)=2000/1000=2

99x36+36=36x(99+1)=36x100=3600
735-208=735-200-8=535-8=527
243-95=243-100+5=143+5=148
245-125+355-175=245+355-(125+175)=600-300=300

102x56
=100x56+2x56
=5600+112
=5712
864-299
=864-(300-1)
=864-300+1
=564+1
=565
25x24=25x4x6=100x6=600
125x32=125x4x8=1000x8=8000
540|2|27=540/27/2=20/2=10
8900|25|4=8900/(25*4)=8900/100=89
2000|8|125=2000/(8*125)=2000/1000=2
99x36+36=36x(99+1)=36x100=3600
735-208=735-200-8=535-8=527
243-95=243-100+5=143+5=148
245-125+355-175=245+355-(125+175)=600-300=300