In fact, this problem is a fill-in-the-blank problem in primary school mathematics. The original title is: □ +□ =□ +□ = □ +□ = □ +□

The answer is: 0+9= 1+8=2+7=2+6=4+5.

Analysis: The sum of every two boxes in the title is the same. This technique combines the largest number with the smallest number, then combines the second largest number with the second smallest number, and so on.

Skills of filling in the blanks by expanding data figures;

1, quantitative type, requires candidates to fill in numerical values, number sets or quantitative relations, such as: solution of equations, solution set of inequalities, definition domain, range of functions, maximum or minimum values, line segment length, angle size, etc.

2. Qualitative type, it is required to fill in a certain property or an object with a given mathematical object, such as the directrix equation, focus coordinates, eccentricity, etc. of a given conic.