(共17张PPT)
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
14
37
42
63
96
78
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
14
37
42
63
78
96
123456789
10
15
14
16
15-1
15+1
19
21
20-1
20+1
20
你能发现什么?
18-1
=
18+1
=
17
19
18
17
19
17和19是18的相邻数。
37-1
=
37+1
=
50-1
=
50+1
=
36
38
49
51
60
70
63
63
=
70
7
+
25+
=
30
36+
=
40
49+
=
50
64+
=
70
81+
=
90
98+
=
100
5
1
9
4
6
2
60
63
70
63
=
60
3
-
21-
=
20
33-
=
30
48-
=
40
77-
=
70
56-
=
50
94-
=
90
1
4
8
7
6
3
24
20
30
24-4
24+6
55
50
60
68
60
70
83
80
90
55-5
68-8
83-3
55+5
68+2
83+7
17+3
=
7+3
=
37+3
=
10
20
40
4+6
=
44+6
=
24+6
=
38+2
=
58+2
=
8+2
=
10
30
50
10
40
60
6+
=
10
49-
=
40
92-
=
90
73+
=
80
86-
=
100-
=
25+
=
3+
=
4
9
7
2
10+30=
70-20=
59+1=
30-1=
100-10=
99+
1=
86+4=
52+
8=
25-
5=
66-6=
40-
2=
46-
1=
79-1=
15+
5=
80+20=
85+
=
100
49-
=
40