②5、2、6、2、8、2、 1 1、2、 15、2、( )、2、26。

③ 13、3 1、24、42、35、53、()、( )、57、75。

④ 1, 3, 5, 7, (), () and () are all () numbers, and 2, 4, 6, 8, (), () and () are all () numbers.

2. Brothers and sisters each have 12 water strokes. After writing and drawing with the same amount of water strokes, my brother left 1 and my sister left ().

3. Small class children go out to take pictures. The teacher is worried that students will fall behind. Count yourself 6 from the back to the front, and 7 from the back. You said that a * * has () children.

4. Xiao Li read 1 page on the first day, and then read 1 page more every day than the day before. On the fourth day, she read page ().

5, a wooden stick with 2 cut 1 time, with () cut twice.

6. There are six black chess and six white chess in the chess box, which are put together in disorder. To touch them from the chess box, at least () pieces must be touched to ensure that they are matched into a pair of socks with the same color.

7. (1) Cobanawa six children lined up, Xiaohua stood in the second place, and there should be () children behind Xiaohua.

(2) The monitor lines up to do exercises, with the seventh counting him from the front and the sixth counting him from the back. Xiaoqing has () people in this team.

(3) The monitor lines up to do exercises. There are seven students in front of him and six students behind him. There are () people in this team.

8. My father bought some peaches, my mother ate two, and my brother and father each ate 1, just half of them. Let dad buy () apples.