Quiz & test questions Grade 9 Math

Varmoor Utility Operations Math: A Grade 9 Unit Test

A grade 9 unit test on the fictional Varmoor utility, mixing multiple-choice, short-answer, and computation items on the pounds formula, flow conversions, and pressure.

Objectives

  1. Students will apply the pounds formula and flow conversions to utility quantities.
  2. Students will find pressure from water height using the standard constant.
  3. Students will interpret and solve a linear tank-drain model.

Vocabulary

Key words: pounds formula, flow conversion, pressure, linear model, slope

Teacher overview

This 40-minute unit test, worth 30 points total, checks grade 9 skills on the fictional Varmoor utility. It mixes multiple-choice, short-answer, and computation items. Students apply the pounds formula, convert flow units, find pressure from water height, and interpret a linear tank-drain model.

Answer Key

  1. Answer: A) 694 gpm. One MGD equals 694 gallons per minute.
  2. Answer: A) mg/L x MGD x 8.34. This is the pounds formula for daily chemical loading.
  3. Answer: 83.4 lb/day. 2.5 mg/L x 4 MGD x 8.34 = 83.4 pounds per day. (2.5 x 4 = 10; 10 x 8.34 = 83.4.)
  4. Answer: 56 psi. 130 ft x 0.433 = 56.29, about 56 psi.
  5. Answer: A) 20 psi. Most states require at least 20 psi at every connection to prevent backflow.
  6. Answer: 2,082 gpm. 3 MGD x 694 gpm per MGD = 2,082 gpm.
  7. Answer: 380,000 gal. V = 500,000 - 20,000(6) = 500,000 - 120,000 = 380,000 gallons.
  8. Answer: 25 hours. 0 = 500,000 - 20,000t, so 20,000t = 500,000 and t = 25 hours.
  9. Answer: The tank loses 20,000 gallons for each hour that passes.
  10. Answer: A) 0.3 NTU. Finished water must stay at or below 0.3 NTU in 95 percent of samples.

Differentiation

Support

Provide a formula strip listing the pounds formula, "1 MGD equals 694 gallons per minute," and "pressure equals height times 0.433," with one worked example of each that is not on the test. Allow a calculator on all computation items.

Extension

Ask students to find at what hour the Varmoor tank in items 7 and 8 is exactly half full, and to explain how they used the drain model to get there.

ELL supports

Provide the formula strip with a small labeled diagram for each formula, such as a tower for pressure and a pipe for flow. Let students answer item 9 with a sentence frame: "The slope means the tank ___ each hour."