运算律,义务教育教科书苏教版四下,理一理,理一理,理一理,判一判,判一判,判一判,判一判,24,判一判,判一判,(2519)4,(2519)4,998989,998999,10143,4399,(2519)4,(2519)4,(2519)4,(2519)4,= 25419,= 10019,= 1900,= 254194,= 10076,= 176,998989,998999,= (991)89,= 10089,= 8900,= (891)99,= 9099,= 8910,1,1,10143,9943,= (1001)43,= 1004343,= 430043,= 4343,= (1001)43,= 1004343,= 430043,= 4257,(2519)4,(2519)4,998989,998999,10143,4399,3518,简便运算,简便运算,3518,= 5718,= 5187,= 907,= 630,3518,= 3529,= 709,= 630,3518,= 5729,= (52)(79),= 1063,= 630,3518,= (305)18,= 3018518,= 54090,= 630,3518,= 35(108),= 3510358,= 350280,= 630,3518,= 35(202),= 3520352,= 70070,= 630,填一填,3216,请根据前一个乘法算式，补充后一个乘法算式，是它能用乘法分配律进行简便运算。,试一试,99999999994,=(91)(991)（9991）(99991),=10100100010000,=11110,试一试,369872,= 3698362,= 36(982),= 36100,= 3600,试一试,3605248036,= 3605248360,= 360(5248),= 360100,= 36000,试一试,1999999,= 999999,= (991)99100,100,= 10099100,= 9900100,= 10000,