1、十几减8、7、6,开火车啦!,6,4,8,7,9,我爱动脑筋:,你是怎样算出15-9=6这个得数的呢?,6,15-9=6,10-9=( ),1+( )=( ),破十法,想加算减法,1,5,6,12-8=,4,还剩几个?,想:,10-8=2,2+2=4,一共有12个风车。,我们要买8个。,12-8=4,还剩几个?,8+( )=12,4,12 - 8 = 4,想加法算减法,想:,13-7=,13-6=,13-7=,想:,10-7=3 3+3=6,6,想:7+( )=13,13-7=6,6,13-6=,想:,10-6=4 3+4=7,7,想:6+( )=13,13-6=7,7,13-7=6,13-6
2、=7,想:7+6=13,书本P15.3,138=5,158=7,168=8,128=4,118=3,148=6,178=9,108=2,127=5,147=7,167=9,137=6,117=4,157=8,116=5,156=9,146=8,166=10,136=7,138=5,158=7,168=8,128=4,118=3,148=6,178=9,108=2,127=5,147=7,167=9,137=6,117=4,157=8,116=5,156=9,146=8,166=10,136=7,退位减,我会算: 十几减8,几加2, 十几减7,几加3, 十几减6,几加4,,十几减9,几加1,,小结:这堂课你学到了什么知识?这堂课我们学习了20以内退位减法中的十几减8、7、6。学会了用多种方法计算,同学们在计算时,选一种自己喜欢的方法算。,