OperatorMaster
Practice QuestionsPractice ExamMath CenterCoursesPremiumAbout
Start Practicing
OperatorMaster

Free study tools for water and wastewater operators.

AccountSettingsAboutVideo ToursPricing and PaymentExam Prep BooksGet the iPhone AppSupportPrivacyTermsExam Disclaimer

Appearance

Operator Master is independent and is not affiliated with WPI, PSI, ABC, the Washington State Department of Ecology or any other state or provincial certification agency.
← Back to MathHow to Use a Pie Wheel
Page 4 of 8
Jump to a Lesson
1. Pie Wheel Basics2. Find the Top3. Find a Bottom4. Place the Numbers5. Choose a Wheel6. Three-Part Wheel7. Find the Dose8. Guided Practice

Lesson 4

Where Do the Numbers Go?

The units decide where a number goes. If the units don't match the section, convert first.
Detention TimeTap a section to cover the quantity you want to find.

Place each number by its units, not by its size. The same number can belong in different sections:

2 MGD belongs with Flow.2 mg/L belongs with Dose or Concentration.2 ft/s belongs with Velocity.
Units don't match the section?Convert first, then use the wheel. A flow in MGD does not go in a section marked gal/min until it is converted.
PreviousContinue