簡算與計算 (1)(9991*1999.1999+9991.9991*1999)/2.0002 (2)(170+1/12)/13 (3)(8888008*125

簡算與計算 (1)(9991*1999.1999+9991.9991*1999)/2.0002 (2)(170+1/12)/13 (3)(8888008*125

(9991乘1999.1999+9991.9991乘1999)除以2.0002
=(9991×1999×1.0001+9991×1.0001×1999)/2.0002
=9991×1999×2.0002/2.0002
=9991×1999
=19972009
(170+1/12)÷13
=(169+13/12)÷13
=169×1/13+13/12×1/13
=13+1/12
=157/12
8888008*(1/8)*1000
=1111001000