1、16 9 =匚|15 912 914 913 9 =11 916 815 81413 88 =12 8 =11 8 =16 7 =15 7 =14 7 =13 4 =124 =11 414 7 = 口18 9 =15 9 =13 7 =12 7 =匚11 7 =17 8 =16 8 =14 8 = 12 3 =匚13 5 =匚13 8 =匚16 7 =匚12 6 =匚15 9 =匚12 5 =11 614 9 =匚1111 4 =11 2 =11 5 =14 5 =139 =12 4 =15 8 =匚例子:9 + 9 =I允 Ih_i7 + 8 = 口 + 7bII nb9 + 8 =I【重点
2、知识二】破十法:退位减法使用破十法口诀:看大数,分出10,减小数,加剩数 例子:18 - 9 =17 -9 =16 -9 =15-9匚” 1巩固练习:16 - 8 =15 - 8 =14 - 8匚d 巳1 口| 1 8 =口算提升练习题14 5 = 13 - 5 =盯1/ C1J:12- 6 =11 6 =687+6 + 9/r/、,囚11 JI !15- 6 = 口 12 - 6 =匚 12 - 5 =口/ ,5L1 13- 4= 口11 - 5 =匚 14 - 6 = 口16 8=15-9=/ ,13- 7 =16-9 =耳|18 - 9=匚 12 - 7= n 14 - 9=匚9 =匚3 =匚5 =匚12 - 9 =匚勺15 - 8 =匚12 - 9 =口13 - 8=11 - 3 = 口11 - 6 二匚 12 - 5 二匚