Double the red light;

* * * three hundred and eighty-one,

How many tips are there at the tip?

The prompt is 192 light.

Just like an "algebra application problem", you can get the answer with a little thinking. Because the number of lights on the first floor to the seventh floor is multiple, if the number of lights on the first floor is "X", then the number of lights on the second floor to the seventh floor is 2 times, 4 times, 8 times, 16 times, 32 times and 64 times that of the first floor, and the number of lights on the first floor to the seventh floor is 128. So you can calculate that the number of lights on the first floor is 3. 3× 64 = 192, that is, the spire (seventh floor) is 192 lamp. Although this poem is a "mathematical poem", it is still a masterpiece because of its concrete image and easy to understand.