Analysis of this question is the addition of the survey, there are 6 numbers 123456, and the two sums are equal, so we can get:

The two phases add up to 1, add up to 6 and divide by 3=2 1/3=7.

Extended data:

Multiplication is a simple operation of addition and division is a simple operation of subtraction.

Subtraction and addition are reciprocal operations, and division and multiplication are reciprocal operations.

Integer addition and subtraction algorithm;

1, aligned with the same number;

2. Starting from the unit;

3. When the addition reaches dozens, it will be promoted to a higher position; If the subtraction is not enough, subtract 1 from the high position. When this number is added to 10, it will decrease.

Properties of addition operation

From additive commutative law's associative law, it can be concluded that when several addends are added, the positions of addends can be exchanged at will; Or add a few addends first and then add them with other addends, and the sum remains the same. For example: 34+72+66+28 = (34+66)+(72+28) = 200.