十几减876练习ppt课件.ppt

十几减8、7、6练习课,20以内的退位减法,2,复习旧知,11 9 =,12 9 =,13 9 =,14 9 =,15 9 =,16 9 =,17 9 =,18 9 =,2,3,4,5,6,7,8,9,十几减9，是几加1。,你发现了什么？,11 8 =,12 8 =,13 8 =,14 8 =,15 8 =,16 8 =,17 8 =,3,4,5,6,7,8,9,十几减8，是几加2。,你发现了什么？,11 7 =,12 7 =,13 7 =,14 7 =,15 7 =,16 7 =,4,5,6,7,8,9,十几减7，是几加3。,你发现了什么？,11 6 =,12 6 =,13 6 =,14 6 =,15 6 =,5,6,7,8,9,十几减6，是几加4。,你发现了什么？,5,8,1,3,9,4,6,10,7,13,8,5,15,8,7,16,8,8,12,8,4,11,8,3,14,8,6,17,8,9,10,8,2,12,7,5,14,7,7,16,7,9,13,7,6,11,7,4,15,7,8,11,6,5,15,6,9,14,6,8,16,6,10,13,6,7,5,9,8,3,9,17,7,12,5,8,9,6,=,5,11-6=5,8,15-7=8,9,18-9=9,12,-,6,6,6,12,2,7,14,18,13,15,7,8,15,6,9,