The sum of a number divided by 5 and 2 is equal to 6 put it in an equation

Since we are talking about a "sum", we can expect an equation with at least 2 addends. To know which parts of the of the word problem are your addends, it is necessary to take out the terms that are not to be added. Looking at the word problem, "6" is the sum, so therefore it should not be included as an addend. With "6" out of the way, we can now split the word problem into the 2 addends. One being the "number divided by 5" and the other being "2". Writing this in mathematical equation form, it would be:

Let: x = the unknown number

(X/5) + 2 = 6

Additionally, solving for the value of x, since X/5 is one term, it is necessary to isolate that. We can do this by subtracting 2 from both sides of the equation such that:

(X/5) + 2 - 2 = 6 - 2
(X/5) = 4

Multiplying both sides by 5
(X/5) * 5 = 4 * 5
X = 20

Therefore your unknown number is 20

The volume is 2212m cubed