There are two circles in the unit, that is, two identical numbers add up to 8, and the circle must be 4; Looking at the ten digits again, it is obvious that the box is 6; Look at hundreds, because the circle is 4 and the box is 6.

From O+O=8, O=4.

So: 8+□=4, from the meaning of the question, it should be 8+6= 14.

So □=6

Namely: 4+△=(6- 1)

No solution.

Property 1

Adding (or subtracting) the same algebraic expression on both sides of the equation still holds.

If a=b

Then a+c=b+c

Attribute 2

When both sides of the equation are multiplied or divided by the same non-zero algebraic expression, the equation still holds.

If a=b

Then there is a c = b c

Or a÷c=b÷c (c≠0).