(1)56*12.5 (2)99*99+199
(1)56*12.5 = 7*8*12.5=7*(8*12.5)= 7*100=700
(2)99*99+199 = 99*99+99 +100 = 99*(99+1)+100=9900+100=10000
(2)99*99+199 = 99*99+99 +100 = 99*(99+1)+100=9900+100=10000
温馨提示:答案为网友推荐,仅供参考
第1个回答 2009-05-03
56*12.5 =7*(8*12.5 )=7*100=700
99*99+199=(100-1)*99+199
=9900-99+199=10000
99*99+199=(100-1)*99+199
=9900-99+199=10000
第2个回答 2009-05-03
56*12.5
=7*8*12.5
=7*100
=700
99*99+199
=(99+1)(99-1)+1+199
=9800+200
=10000
=7*8*12.5
=7*100
=700
99*99+199
=(99+1)(99-1)+1+199
=9800+200
=10000