1.25×444 2.202×98 3.99×7 4.63×63+63+63×36 5.65×125 6.41×250 7.41×250 8.240×23+76×230
第1个回答 2012-11-24
原式=25*(400+40+4)=11100
原式=202*(100-2)=19398
原式=(100-1)*7=693
原式=63*(63+1+36)=6300
原式=(60+5)*125=1375
原式=(40+1)*250=10250
同6
原式=230*(24+76)=23000
第2个回答 2012-11-24
1)
25×444
=25×(4×111)
=(25×4)×111
=100×111
=11100
2)
202×98
=(100+102)×98
=100×98+102×98
=9800+(100+2)×(100-2)
=9800+100²-2²
=9800+10000-4
=19796
3)
99×7
=(100-1)×7
=100×7-1×7
=700-7
=693
4)
63×63+63+63×36
=63×63+63×1+63×36
=63×(63+1+36)
=63×100
=6300
5)
65×125
=(64+1)×125
=64×125+1×125
=(8×8)×125+125
=8×(8×125)+125
=8×1000+125
=8000+125
=8125
6&7)
41×250
=(40+1)×250
=40×250+1×250
=10000+250
=10250
8)
240×23+76×230
=24×10×23+76×23×10
=(24+76)×10×23
=100×230
=23000本回答被提问者采纳
25×444
=25×(4×111)
=(25×4)×111
=100×111
=11100
2)
202×98
=(100+102)×98
=100×98+102×98
=9800+(100+2)×(100-2)
=9800+100²-2²
=9800+10000-4
=19796
3)
99×7
=(100-1)×7
=100×7-1×7
=700-7
=693
4)
63×63+63+63×36
=63×63+63×1+63×36
=63×(63+1+36)
=63×100
=6300
5)
65×125
=(64+1)×125
=64×125+1×125
=(8×8)×125+125
=8×(8×125)+125
=8×1000+125
=8000+125
=8125
6&7)
41×250
=(40+1)×250
=40×250+1×250
=10000+250
=10250
8)
240×23+76×230
=24×10×23+76×23×10
=(24+76)×10×23
=100×230
=23000本回答被提问者采纳