The analysis process is as follows:

The mathematical expression of the product of two sevens: 7×7, which can be calculated as 7×7=49.

The mathematical expression of the sum of two 7s: 7+7, which can be calculated as 7+7= 14.

It should be noted that there are two 7s, which are 7 and 7, not 2 and 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.