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Mathematical thinking training and answers in senior two.
There is a dice (tóu) (a cube with 1, 2, 3, 4, 5, 6 points on each side) about the second grade math thinking training and the answer 1. From three different angles, the situation is shown in the following figure. Please judge who is right on this dice (tóu).

A: 1: 00 to 6: 00, 2: 00 to 4: 00 and 3: 00 to 5: 00. Using reasoning thinking, we might as well consider whether these points are adjacent. It is not difficult to see from the above three pictures that there are three points in each picture, which are adjacent to one point, two points, four points and six points respectively, so three points can only be opposite to five points. Because there is only 1 on the opposite side, four points will not be opposite to five points. It can also be seen from the picture that four points cannot be opposite to three points, six points and one point, so four points can only be opposite to two points. One more thing and six o'clock can only be relative. So one to six, two to four, three to five.

One day, Big Head's son was making a puzzle: Qiu1+2+3+4+5+6+…+99+100+99+…+13+12+65438. If he can't do it, ask the little head dad, and neither can the little head dad. Can you help the big head son calculate it?

The answer is to observe this question first. If you add 9+8+7+...+3+2+ 1 at the back, you can use the middle number * the middle number to calculate. The specific analysis is as follows:

1+2+3+4+5+6+...+99+ 100+99+...+ 13+ 12+ 1 1+ 10

= 12+3+4+5+6+...+99+ 100+99+...+ 13+ 12+ 1 1+9+8+7+6+5+4+3+2+ 1-(9+8+7+6+5+4+3+2+ 1)

= 100* 100-45

= 10000-45

=9955