19999*9999×9999
=(20000-1)x(10000-1)²
=(20000-1)x(10^8-2x10000+1)
=2x10^12 - 4x10^8 +20000 - 10^8 + 20000 - 1
=2x10^12 - 5x10^8 +40000-1
=10^8 x(20000-5) +39999
=10^8x19995 +39999
=1999500000000+39999
=1999500039999
199399周初初见面计算,简便计算,19999×99999999见面几次不会
19999*9999*9999=(20000-1)*(10000-1)*(10000-1)
19999×(99999÷99999)=19999
19999+9999×9999
=10000+9999+9999×9999
=10000+9999×(1+9999)
=10000+9999×10000
=10000X(1+9999)
=10000×10000
=100000000