人教版四年级数学上册第一单元第十一课时.ppt
用计算器计算,亚东第一小学:丁宝生制作,金蛋1,金蛋2,金蛋3,返回,99991 99992 99993 9999499995 9999799999,金蛋1,9999,19998,29997,39996,49995,69993,89991,112234=111222334=111122223334=,金蛋2,111111222222333334=,111122233334 N个 N个 N-1个,33,333,3333,33333,3333 N个,对计算器这个新朋友说一句最想说的话!,金蛋3,2222222255555555 8个 8个,练一练,25=2255=222555=22225555=,10,1210,123210,12343210,=1234567876543210,11=11 11=111 111=1111 1111=11111 11111=_ _=_,1,121,12321,1234321,123454321,111111,111111,12345654321,用计算器计算,并找一找各组题的规律。,(1)99-1=989-2=9879-3=98769-4=,80,880,8880,88880,987659-5=,9876549-6=,课堂检测A,888880,8888880,用计算器计算,并找一找各组题的规律。,(2)129-8=1239-7=12349-6=123459-5=,100,1100,11100,111100,1234569-4=,12345679-3=,1111100,11111100,(3),1428571142857214285731428574,14285751428576,142857,285714,428571,571428,714285,857142,(4),11111111111111111111,1111111111111111111111,1,121,12321,1234321,123454321,12345654321,用计算器计算,并找一找各组题的规律。,(1)19+99=118+989=117+9879=1116+98769=,100,1000,10000,100000,11115+987659=1000000,111114+9876549=10000000,课堂检测B,用计算器计算,并找一找各组题的规律。,(2)(10-1)9=(200-2)9=(3000-3)9=(40000-4)9=,1,22,333,4444,(500000-5)9=,(6000000-6)9=,55555,666666,(3),49449944499944449999,4444499999,36,4356,443556,44435556,4444355556,(4),353533533533353335,1225,112225,11122225,用计算器算一算,看看红色方框中9个数的和与方框中间的一个数有什么关系。,要使方框内9个数的和是153,该怎样框?,(5),再见,