练习一（100道）
65-19=
40-23=
91-37=
77-18=
42-27=
72-35=
50-15=
93-59=
44-27=
85-27=
90-67=
86-19=
72-54=
78-19=
81-34=
81-37=
63-28=
31-16=
44-29=
92-67=
75-47=
60-23=
95-29=
93-64=
81-17=
70-56=
72-17=
72-47=
82-37=
64-29=
85-29=
31-13=
72-53=
80-18=
70-47=
61-19=
85-28=
86-37=
54-39=
34-16=
94-67=
88-39=
91-14=
62-27=
70-52=
91-67=
83-19=
73-54=
74-19=
73-44=
83-24=
91-22=
33-16=
71-53=
80-16=
91-16=
73-47=
81-22=
83-37=
61-23=
30-16=
92-64=
84-17=
73-56=
75-17=
90-12=
71-47=
60-29=
83-29=
30-13=
96-67=
87-18=
76-47=
66-19=
87-28=
84-37=
58-39=
35-16=
82-13=
81-39=
63-27=
84-27=
75-19=
60-28=
42-29=
93-67=
81-16=
70-51=
84-39=
95-16=
55-39=
96-29=
80-17=
74-56=
73-17=
61-12=
67-29=
71-13=
62-26=
51-39= 练习二（100道）
70-47=
37-19=
97-68=
73-14=
40-13= 82-56=
92-24=
43-25=
80-66=
60-39= 61-14=
94-36=
42-25=
74-36=
94-45= 90-66=
62-48=
60-28=
40-23=
93-48= 91-62=
81-65=
50-39=
41-25=
80-23=
54-18=
93-34=
80-44=
70-12=
55-26=
51-22=
93-35=
71-22=
90-71=
80-63= 64-38=
77-38=
78-19=
85-57=
92-18= 70-34=
96-49=
62-26=
80-25=
95-36= 53-18=
84-37=
81-35=
80-27=
60-38= 93-18=
90-31=
66-28=
64-36=
92-29= 38-19=
50-29=
50-21=
80-43=
55-19=
84-49=
70-22=
34-17=
90-35=
90-49=
40-15=
65-29=
80-33=
94-75=
75-29= 91-38=
70-24=
80-45=
76-49=
82-65= 75-58=
96-47=
86-67=
96-78=
94-38= 68-29=
90-21=
74-26=
50-31=
90-16=
54-39=
63-24=
42-23=
64-35=
93-46= 81-15=
93-74=
58-29=
52-28=
40-25= 70-42=
56-38=
50-17=
63-35=
34-15= 练习三（100道）
80-19=
60-31=
62-28=
40-14=
31-14=
70-58=
70-42=
83-66=
50-27=
43-18= 30-11=
73-38=
80-21=
73-48=
60-18=
65-48=
50-25=
41-14=
80-31=
94-15= 73-37=
76-38=
64-48=
52-33=
46-28= 73-18=
90-33=
46-18=
83-26=
67-39= 67-49=
34-19=
80-11=
73-28=
33-19= 60-28=
80-43=
92-53=
65-28=
64-19= 94-45=
30-14=
84-26=
64-18=
53-15= 92-75=
52-27=
77-38=
70-12=
83-16= 71-37=
53-25=
80-23=
92-23=
41-28= 72-18=
73-34=
52-17=
64-28=
90-63= 70-48=
70-22=
83-36=
37-19=
82-43= 67-19=
51-23=
40-21=
80-33=
65-18= 50-15=
80-61=
94-75=
41-18=
84-66= 92-25=
52-25=
82-23=
51-33=
92-33= 80-41=
84-56=
92-35=
90-53=
30-19= 70-28=
31-19=
70-32=
82-33=
94-25=
70-37=
62-48=
43-14=
34-15=
43-28= 50-17=
92-63=
64-39=
94-35=
72-48=
练习四（100道）
70-53=
51-38=
61-39=
82-28=
71-56=
54-35=
82-55=
41-17=
92-76=
70-14= 76-47=
76-48=
65-38=
65-36=
84-29= 62-33=
90-19=
86-59=
74-46=
90-45= 72-33=
91-62=
93-48=
75-29=
83-35= 62-27=
80-23=
93-19=
35-18=
70-46= 71-55=
84-27=
41-12=
94-36=
30-16= 86-58=
72-23=
90-42=
90-31=
90-37= 70-52=
84-66=
66-19=
93-44=
91-78= 42-29=
95-59=
91-15=
83-55=
30-13= 72-43=
63-49=
71-32=
93-65=
95-49= 32-17=
94-49=
93-49=
73-45=
72-24= 86-37=
81-24=
62-37=
32-15=
71-42= 75-37=
83-49=
70-24=
80-24=
90-32= 38-19=
75-48=
33-19=
75-47=
82-59=
92-79=
43-25=
92-54=
92-13=
91-36=
45-29=
73-35=
96-67=
91-46=
80-35= 91-12=
90-54=
80-16=
76-58=
63-38= 70-33=
94-39=
36-19=
30-12=
92-33= 52-29=
82-63=
91-48=
96-79=
61-32= 练习五（100道）
90-53=
96-79=
87-69=
71-33=
94-47= 84-38=
83-47=
60-45=
42-16=
75-27= 91-77=
62-26=
51-29=
70-57=
93-26= 95-67=
81-44=
86-47=
80-26=
80-19= 83-17=
70-37=
31-14=
76-57=
41-12= 84-17=
91-28=
70-34=
93-37=
71-23= 81-27=
63-46=
35-18=
30-16=
70-17= 95-77=
85-59=
93-24=
82-55=
90-32=
92-76=
96-47=
71-44=
64-36=
75-19= 87-68=
60-28=
93-17=
46-28=
95-66= 81-32=
85-27=
61-18=
92-19=
50-39= 72-56=
81-26=
61-22=
84-18=
83-37= 68-19=
81-29=
92-38=
50-35=
40-13= 91-27=
83-48=
45-16=
32-13=
43-26= 81-49=
85-17=
80-29=
80-14=
86-58= 33-14=
95-27=
31-15=
70-51=
41-13= 90-59=
91-23=
53-29=
44-15=
93-34= 71-27=
82-36=
63-49=
65-29=
53-34= 42-13=
88-59=
30-13=
70-14=
62-19= 82-58=
85-67=
92-73=
60-27=
65-36=
