The average of a set of numbers is calculated by dividing the sum of the numbers by the total number of numbers. If the average of seven numbers is 12, we can use the formula for the average:

$\text{Average} = \frac{\text{Sum of the numbers}}{\text{Number of numbers}}$

Given that the average is 12 and the number of numbers is 7, we can write:

$12 = \frac{\text{Sum of the numbers}}{7}$

To find the sum of the numbers, multiply both sides of the equation by 7:

$\text{Sum of the numbers} = 12 \times 7 = 84$

So, the sum of the seven numbers is 84.

Would you like more details or have any questions? Here are some related questions:

1. How do you calculate the average of a set of numbers?
2. How can you find the sum if the average and the number of terms are known?
3. What if the average was a decimal? How would that affect the sum?
4. Can you find the average if you only know the sum?
5. What is the relationship between sum, average, and number of terms?

Tip: Remember that multiplying the average by the number of items always gives you the total sum.