六年级简算题654321*123456-654322*123455

问题描述:

六年级简算题654321*123456-654322*123455

因为
654321*123456
=(654322-1)*(123455+1)
=654322*123455+(654322-123455-1)
所以
654321*123456-654322*123455
=654322-123455-1
=530866

答:
原式
=654321*123456-(654321+1)*123455
=654321*(123456-123455)-123455
=654321-123455
=530866

654321×123456-654322×123455
=654321×(1+123455)-(654321+1)×123455
=654321×1+654321×123455-654321×123455-1×123455
=(654321×123455-654321×123455)+(654321×1-1×123455)
=0+530866
=530866