手脑速算教程及练习(7)

28+49-16+8-42=                          15+8+64-53+58=

56+7+28-81+30=                          36+48+13-24-63=

47+29-33+18-41=                         8+9+17+44-68=

5+39-22+38+34=                          57-54+9+39+48=

27+16-39+58+23=                         63+24-69+34+22=

62-38+15+33-26=                          54-28+33+14-15=

减9就是加1，左手减10  减8就是加2，左手减10  减7就是加3，左手减10  减6就是加4，左手减10
减5就是加5，左手减10  减4就是加6，左手减10  减3就是加7，左手减10  减2就是加8，左手减10
减1就是加9，左手减10
二、 100以内的混合运算练习
74-18+23-16+9=                         87-19-24+14+8=

66-38+12+7-8=                          54+16-23+4+7=

92-28+16-35-8=                          73-35+12-7+5=

27+17-26+8+63=                         64-16+27+9-28=

72-24+13-19+18=                         63-15-18+17+39=

87-38+15+9-24=                          91-38+19-28+4=

28+44+27-55-41=                   35+7+24-33-3=

18+29-25-12+78=                   56+28-44+25-5=

47+39-64+14-2=                    99-87+54-52+17=

56+26-22+18-44=                   58-34+29-22+28=