,做个乘法表,返回,北师大版 数学 二年级 上册,做个乘法表,课前导入,探究新知,课堂小结,课后作业,6,9,的乘法口诀,课堂练习,8,北师大版 数学 二年级 上册做个乘法表课前导入探究新知,课前导入,我们学完了,1,9,的乘法口诀，你能熟练的背诵出来吗？,这节课我们就来整理这单元的知识。,44=,56=,72=,59=,48=,25=,86=,38=,67=,16,30,14,45,32,10,48,24,42,课前导入我们学完了19的乘法口诀，你能熟练的背诵出来吗？这,2,这些算式的积都是,18,。,把哪些算式排在一起？,这些算式乘数中都有,3,。,做个乘法表,这些算式的积都是18。把哪些算式排在一起？这些算式乘数中都有,3,探究新知,1,2,3,4,5,6,7,8,9,3,3,3,3,3,3,3,3,3,乘数,乘数,积,3,6,9,12,15,18,21,24,27,找出乘数中有,3,的乘法算式，并完成下表。,探究新知123456789333333333乘数乘数积369,4,找出积是,18,的乘法算式，并填一填。,三六十八,二九十八,2,9,18,18,9,2,3,6,6,3,18,18,找出积是18的乘法算式，并填一填。三六十八二九十八2,5,下面是淘气做的乘法表，你能帮他填完整吗？,1,2,3,4,5,6,7,8,9,1,81=,2,72=,3,63=,4,24=,94=,5,35=,55=,6,46=,7,27=,77=,97=,8,48=,58=,9,39=,69=,89=,12=2,13=3,14=4,15=5,16=6,17=7,18=8,19=9,21=2,23=6,8,25=10,26=12,14,28=16,29=18,31=3,32=6,33=9,34=12,15,36=18,37=21,38=24,27,41=4,42=8,43=12,44=16,45=20,24,47=28,32,49=36,51=5,52=10,53=15,54=20,25,56=30,57=35,40,59=45,61=6,62=12,18,64=24,65=30,66=36,67=42,68=48,54,71=7,14,73=21,74=28,75=35,76=42,49,78=56,79=63,8,82=16,83=24,84=32,85=40,86=48,87=56,88=64,72,91=9,92=18,93=27,36,95=45,96=54,63,98=72,99=81,22=4,11=1,下面是淘气做的乘法表，你能帮他填完整吗？123456789,6,观察下表，你发现了什么？,1,2,3,4,5,6,7,8,9,1,11=1,81=,2,22=4,72=,3,63=,4,24=,94=,5,35=,55=,6,46=,7,27=,77=,97=,8,48=,58=,9,39=,69=,89=,12=2,13=3,14=4,15=5,16=6,17=7,18=8,19=9,21=2,23=6,8,25=10,26=12,14,28=16,29=18,31=3,32=6,33=9,34=12,15,36=18,37=21,38=24,27,41=4,42=8,43=12,44=16,45=20,24,47=28,32,49=36,51=5,52=10,53=15,54=20,25,56=30,57=35,40,59=45,61=6,62=6,18,64=24,65=30,66=36,67=42,68=48,54,71=7,14,73=21,74=28,75=35,76=42,49,78=56,79=63,8,82=16,83=24,84=32,85=40,86=48,87=56,88=64,72,91=9,92=18,93=27,36,95=45,96=54,63,98=72,99=81,横着看，每一行都是相同个数增加的。,是几的口诀,它们的积就依次相差几。,观察下表，你发现了什么？123456789111=18,7,1,2,3,4,5,6,7,8,9,1,11=1,81=,2,22=4,72=,3,63=,4,24=,94=,5,35=,55=,6,46=,7,27=,77=,97=,8,48=,58=,9,39=,69=,89=,12=2,13=3,14=3,15=5,16=6,17=7,18=8,19=9,21=2,23=6,8,25=10,26=12,14,28=16,29=18,31=3,32=6,33=6,34=12,15,36=18,37=21,38=24,27,41=4,42=8,43=12,44=16,45=20,24,47=28,32,49=36,51=5,52=10,53=15,54=20,25,56=30,57=35,40,59=45,61=6,62=6,18,64=24,65=30,66=36,67=42,68=48,54,71=7,14,73=21,74=28,75=35,76=42,49,78=56,79=63,8,82=16,83=24,84=32,85=40,86=48,87=56,88=64,72,91=9,92=18,93=27,36,95=45,96=54,63,98=72,99=81,竖着看，第几列就用几开头。,123456789111=181=222=472=,8,1,2,3,4,5,6,7,8,9,1,11=1,81=,2,22=4,72=,3,63=,4,24=,94=,5,35=,55=,6,46=,7,27=,77=,97=,8,48=,58=,9,39=,69=,89=,12=2,13=3,14=3,15=5,16=6,17=7,18=8,19=9,21=2,23=6,8,25=10,26=12,14,28=16,29=18,31=3,32=6,33=6,34=12,15,36=18,37=21,38=24,27,41=4,42=8,43=12,44=16,45=20,24,47=28,32,49=36,51=5,52=10,53=15,54=20,25,56=30,57=35,40,59=45,61=6,62=6,18,64=24,65=30,66=36,67=42,68=48,54,71=7,14,73=21,74=28,75=35,76=42,49,78=56,79=63,8,82=16,83=24,84=32,85=40,86=48,87=56,88=64,72,91=9,92=18,93=27,36,95=45,96=54,63,98=72,99=81,斜着看，乘数相同的算式成一条直线。,123456789111=181=222=472=,9,1,2,3,4,5,6,7,8,9,1,11=1,81=,2,22=4,72=,3,63=,4,24=,94=,5,35=,55=,6,46=,7,27=,77=,97=,8,48=,58=,9,39=,69=,89=,12=2,13=3,14=3,15=5,16=6,17=7,18=8,19=9,21=2,23=6,8,25=10,26=12,14,28=16,29=18,31=3,32=6,33=6,34=12,15,36=18,37=21,38=24,27,41=4,42=8,43=12,44=16,45=20,24,47=28,32,49=36,51=5,52=10,53=15,54=20,25,56=30,57=35,40,59=45,61=6,62=6,18,64=24,65=30,66=36,67=42,68=48,54,71=7,14,73=21,74=28,75=35,76=42,49,78=56,79=63,8,82=16,83=24,84=32,85=40,86=48,87=56,88=64,72,91=9,92=18,93=27,36,95=45,96=54,63,98=72,99=81,交换乘数的位置积是相同的。,123456789111=181=222=472=,10,课堂练习,把乘法口诀填完整。,三七（）,五九（）,七九（）,七八（）,四六（）,六六（）,五七（）,八八（）,二十一,四十五,六十三,五十六,三十六,三十五,六十四,二十四,课堂练习把乘法口诀填完整。三七（）五九（,11,3,6,18,根据乘法口诀“三六十八”能选,3,6,和,18,。,18,3,6,3,18,18,6,3,从“,18,27,3,9,6,”中选出几个数，组成两道乘法算式和两道除法算式。,6,3618根据乘法口诀“三六十八”能选3,6和18。183,12,3,9,27,根据乘法口诀“三九二十七”可以选,3,9,和,27,。,27,3,9,3,27,27,9,3,从“,18,27,3,9,6,”中选出几个数，组成两道乘法算式和两道除法算式。,9,3927根据乘法口诀“三九二十七”可以选3,9和27。27,13,八五折,58=,五八四十,40,（人）,答：座位够了。,有,5,张空桌。,我们有,38,人。,座位够吗？,一张桌子能坐,8,个人。,40,35,八五折58=五八四十40（人）答：座位够了。有5张空桌。我,14,八五折,想一想，算一算。,3=13,6,6=23,9=33,1+2+3=6,3+6+9=3,八五折想一想，算一算。3=1366=239=331+2,15,八五折,想一想，算一算。,2+4+8=2,2=12,7,4=22,8=42,1+2+4=7,八五折想一想，算一算。2+4+8=22=1274,16,算一算,10,69=,45=,41=25=,88=,74=,19=27=,44=,66=,87=48=,99=,22=,67=6+7=,54,16,36,56,32,20,4,64,28,9,14,81,4,42,13,算一算1069=45=41=,17,4,5,6,7,8,9,4,4,4,4,4,4,乘数,乘数,积,4,8,12,16,20,24,28,32,36,找出乘数中有,4,的乘法算式，并完成下表。,1,2,3,4,4,4,456789444444乘数乘数积4812162024283,18,这节课你们都学会了哪些知识？,横着看,，是几的口诀，他们的积就依次相差几。每一行都是相同个数增加的。,课堂小结,乘法口诀表,竖着看,，第几列就用几开头,这节课你们都学会了哪些知识？横着看，是几的口诀，他们的积就依,19,1.,从教材课后习题中选取；,2.,从课时练中选取。,课后作业,1.从教材课后习题中选取；课后作业,20,