《有趣的算式》完整版ppt课件.ppt

执教者：万玉娟,义务教育教科书四年级上册,有趣的算式,执教者：万玉娟,有趣的算式,义务教育教科书四年级上册,执教者：万玉娟,有趣的算式,111111111111=,算一算：,12345654321,11,1111,111111,11111111,121,12321,1234321,123454321,回文数,算一算，然后认真观察，说一说你发现了什么。,1111111111,1,不计算，你能直接写出999999999999的积吗？,999999999999,？,不计算，你能直接写出999999999999的积吗？,999999999999,999998000001,观察下面的算式和得数有什么特点，填一填，你发现有什么规律？,192,1293,12394,123495,123459 ,11,111,1111,123456 ,11111,111111,1111111,6,9,7,1、奇怪的142857计算并观察下面算式得数的特点，你能直接写出宝盒上算式的得数并找到密码吗？,1428571=,1428572=,1428573=,1428574=,142857,285714,428571,571428,1428575=,1428576=,1、奇怪的142857计算并观察下面算式得数的特点，你能直接写出宝盒上算式的得数并找到密码吗？,1428571=,1428572=,1428573=,1428574=,142857,285714,428571,571428,1428575=,1428576=,714285,857142,1428577=999999,有趣的算式,142857=999,142857=99,1 8 1 = 912 8 2 = 98123 8 3 = 9871234 8 4 = 987612345 8 5 = 98765123456 8 6 = 9876541234567 8 7 = 987654312345678 8 8 = 98765432123456789 8 9 = 987654321,1 9 2 = 1112 9 3 = 111123 9 4 = 11111234 9 5 = 1111112345 9 6 = 111111123456 9 7 = 11111111234567 9 8 = 1111111112345678 9 9 = 111111111123456789 9 10= 1111111111,9 9 7 = 8898 9 6 = 888987 9 5 = 88889876 9 4 = 8888898765 9 3 = 888888987654 9 2 = 88888889876543 9 1 = 8888888898765432 9 0 = 888888888,1 1 = 111 11 = 121111 111 = 123211111 1111 = 123432111111 11111 = 123454321111111 111111 = 123456543211111111 1111111 = 123456765432111111111 11111111 = 123456787654321111111111 111111111 = 12345678987654321,你有什么收获？,