凑十法,破十法 综合练习题. 姓名_____
进位加法(凑十法口诀:看大数,分小数,凑成十,算得数。) 一九一九好朋友,二八二八手拉手,三七三七真亲密, 四六一起走,五五五五一双手,大数记心里,小数记手里。 退位减法(破十法口诀:看大数,分出10,减小数,加剩数。)
十几减9,几加1;十几减8,几加2;十几减7,几加3,;十几减6,几加4,;十几减5,几加5; 十几减4,几加6;十几减3,几加7;十几减2,几加8;十几减1,几加9;破大数,加小数。
9 + 2 = 9 + 3 = 9 + 4 = 9 + 5 = 9 + 9 + 8 = 9 + 9 = 8 + 8 + 4 = 8 + 5 11 - 9 = 12
14 - 9 = 15
17 - 9 = 18
12 - 8 = 13 15 - 8 = 16 6 = 9 + 7 = = 8 + - 9 = 13 - 9 = 16 - 9 = 11 - 8 = - 8 = 17 3 = 6 = - 9 = - 9 = - 8 = 14 - 8 = - 8 =
11 - 7 = 12 - 7 = 13 - 7 =
14 - 7 = 15 - 7 = 16 - 7 =
11 - 6 = 12
8 + 7 = 8 + 7 + 4 = 7 + 7 + 7 = 7 + 4 = 7 + 5 = 6 + 5 = 6 + 9 + 6 = 6 + 5 = - 6 = 13 8 = 8 + 5 = 7 + 6 = - 6= 5 = 6 = 8 + 7 = 9 + 9 =