Introduction - Basic Mathematics for Water and Wastewater Operators - page 3

• Volume is the capacity of the unit (how much it will hold), measured in

cubic units (cubic feet, cubic meters) or in liquid volume units (gallons,
liters, million gallons).

• Width is the distance from one side of the tank to the other, measured in

linear units.

C alCulation s teps
Standard methodology used in making mathematical calculations includes the
following:

1. If appropriate, make a drawing of the information in the problem.

2. Place the given data on the drawing.

3. Ask “What is the question?” followed by “What are they really looking for?”

4. If the calculation calls for an equation, write it down.

5. Fill in the data in the equation—look to see what is missing.

6. Rearrange or transpose the equation, if necessary.

7. If available, use a calculator.

8. Always write down the answer.

9. Check any solution obtained. Does the answer make sense?

Note: Solving word math problems is difficult for many operators. Solving these
problems is made easier, however, by understanding a few key words.

K ey W ords
• Of means to multiply.

• And means to add.

• Per means to divide.

• Less than means to subtract.

C alCulators
The old saying “Use it or lose it” amply applies to mathematics. Consider a person
who first learned to perform long division, multiplication, square roots, adding and
subtracting, converting decimals to fractions, and other math operations using noth-
ing more than pencil and paper and his or her own brain power. Eventually, this
same person is handed a pocket calculator that can produce all of these functions
and much more simply by manipulating certain keys on a keyboard. This process
involves little brainpower—nothing more than punching in correct numbers and
operations to achieve an almost instant answer. Backspacing to our earlier statement
of “Use it or lose it” makes our point. As with other learned skills, how proficient we
remain at performing a learned skill is directly proportional to the amount of time
we spend using the skill—whatever that might be. We either use it or lose it. The
consistent use of calculators has caused many of us to forget how to perform basic
math operations with pencil and paper—for example, how to perform long division.