1、十 几 减 9、8、7、6的退位减法,人教版一年级数学下册,?,教学目标,掌握十几减9、8、7、6的计算方法。能理解十几减9、8、7、6的退位减法的算理,能正确地进行计算。进一步感知加减法算式之间的联系,促进计算能力的提高。,13 15 ( )10 ( ) 5 ( ) 7 10,14 16 ( )( ) 10 6 ( ) 10 2,3,10,17,4,10,12,?,10-8= 10-9= 10-6= 10-5= 12-2= 17-7= 11-1= 15-2= 10-7=10-6=13-3= 18-8=,有13个气球。,布置房间要用9个。,还剩多少个,?,13-9=?,13-9=?,4,13-
2、9=?,4,13=10+310-9=11+3=4,9=3+6 13-3=1010-6=4,9+4=13 13-9=4,15 8 =13 7 =11 6 =,?,14 8 = 12 9 = 11 7 = 13 6 = 16 7 = 15 8 = 17 9 = 16 8 = 18 9 =,用你自己喜欢的方法算一算,?,9 = 8 =11 7 = 6 =,6 = 7 =12 8 = 9 =,2,3,4,5,6,5,4,3,?,15 9 = 5 + 9 = 7 + 9 = 13 8 = 7 + 5= 18 9 = 16 8 = 2 + 9 =17 9 = 11 7 = 12 9 = 11 8 =,( 注 意 +、 号 ),?,( ) ( )= 7,?,?,