1
3
5
10
8
6
4
2
20
18
17
14
4 + 3 =
10 - 2 =
12 - 7 =
7 + 9 =
14 + 5 =
10 - 6 - 0 =
11 + 6 + 2 =
8 - 3 + 9 =
19 - 10 - 5 =
9元
5元
8元
3元
滴水量/毫升
15
30
45
60
75
……
时间/分
67+28= 960﹣540= 1.6×5= 7.5+2.7=
= = 53÷100= =
问:这两条绳子原来的长度是多少厘米?