This sentence is part of the stem. The original title is "The Magic Box keeps changing, and a hundred tables are gone. Can you guess the sum of the five numbers now covered? "

This topic is a primary school math problem, the answer is 220.

The magic box means that the sum of nine numbers in the frame is nine times the middle number, and the hundred tables are the content of mathematics in the first grade of primary school, which is used to let students know more clearly the arrangement order of numbers within 100.