Introduction To Average
The average of two numbers are calculated by taking their sum and dividing it by $2$. Let us say that $A$ has $10$ pencils and $B$ has $14$ pencils. Then the average number of pencils they have is $(10 + 14) \div 2 = 24 \div 2 = 12$.
If we take any two numbers on the number line, their average would be the midpoint of those two numbers. Look at the number line below:
The average of $4$ and $8$ is $(4 + 8) \div 2 = 12 \div 2 = 6$, which is the mid-point of $4$ and $8$.
Similarly the average of $1$ and $7$ is $(1 + 7) \div 2 = 8 \div 2 = 4$, which is the mid-point of $1$ and $7$.
Average in other words also means what would be the number for each if the same sum was distributed between the two.
Let us take and example of this.
$A$ has $15$ candies, and $B$ has $23$ candies. How many candies should $B$ give to $A$ such that they have an equal number of candies.
We know that if both of them have the same number of candies, without changing the total candies they would have the average number of candies, hence they would have $(15 + 23) \div 2 = 38 \div 2 = 19$ candies each.
Hence $B$ would have to give $23 - 19 = 4$ candies to $A$.
We will see more such problems during your assignments.