Quiz & test questions Grade 4 Social Studies & Civics

How Corven Bay Changed After Its Sea Water Plant

A grade 4 quiz using a then-and-now table for a fictional coastal town that began making drinking water from sea water, with measurement and time word problems.

Grade: Grade 4
Subject: Social Studies & Civics
Material: Quiz & test questions
Time: 30 min
Prep: No prep
Materials: None

Standards

D2.Geo.5.3-5 C3 Framework

Explain how the cultural and environmental characteristics of places change over time.

How this material aligns: Items 1, 2, 6, and 7 ask students to read a then-and-now table and explain how the town's water source, its jobs, and its dry-summer rules changed over time.

All materials for D2.Geo.5.3-5 →

4.MD.A.1 Common Core Math

Know relative sizes of measurement units within one system of units including km, m, cm; kg, g; lb, oz; l, ml; hr, min, sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit. Record measurement equivalents in a two-column table.

How this material aligns: Item 5 converts hours into minutes, expressing a measurement given in a larger unit in terms of a smaller unit exactly as this standard requires.

All materials for 4.MD.A.1 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-09-04.

Objectives

Students will use a then-and-now table to describe how a town's water source changed.
Students will subtract and multiply multi-digit numbers set in a town water scenario.
Students will convert a measurement in hours into minutes.
Students will name one cost a town paid when it changed how it gets water.

Vocabulary

Key words: sea water, salt, well, dock, water plant

Teacher overview

This 30-minute quiz is worth 24 points and follows the fictional coastal town of Corven Bay from 1970 to today. It mixes two multiple-choice items, two short-answer items, and three computation items, all built on a then-and-now table students read at the start. One point is worth making before students start. Taking the salt out of sea water sounds like a town solving its water problem for good, yet the process costs a great deal of energy, so towns that do it still watch their use and still keep their wells. Item 7 is where that idea gets tested.

How Corven Bay Changed After Its Sea Water Plant — Grade 4 Social Studies & Civics

Name: ____________________________ Date: ______________

Assessment

Read the table about the town. Then answer the questions.

Corven Bay is a fictional town on the coast. Long ago its wells turned salty. In 2005 the town built a plant that takes the salt out of sea water and makes it safe to drink.

Corven Bay	Then (1970)	Now
Where the water came from	5 town wells	The sea water plant and 2 wells
People living in town	1,400	3,600
Boats working from the dock	6 fishing boats	6 fishing boats and 2 tour boats
Water in a dry summer	The town shut off water some afternoons	Water runs all year
Water jobs in town	2 well workers	9 plant workers and 2 well workers

(3 points) What changed most about where Corven Bay gets its water?
- A) The town stopped using wells and now uses only sea water.
- B) The town added a sea water plant and kept 2 of its wells.
- C) The town buys all of its water from another town.
- D) The town gets its water from rain barrels.
(3 points) Use the table. Write one way the town looks different now than it did in 1970.
(4 points) The table says 1,400 people lived in Corven Bay in 1970 and 3,600 people live there now. How many more people live in the town now?
(4 points) The Corven Bay plant makes 4,000 gallons of drinking water each hour. How many gallons does it make in 6 hours?
(4 points) Workers clean the plant's filters for 2 hours every morning. How many minutes is that?
(3 points) Which sentence best explains why Corven Bay built the plant?
- A) The town wanted a building that tourists could visit.
- B) The town's wells turned salty and the town ran short in dry summers.
- C) The town had too much water and needed a place to put it.
- D) The town wanted to sell salt.
(3 points) The town gained something when it built the plant. Name one cost the town paid for that change.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Answer: B.
The table lists the sea water plant and 2 wells in the Now row, so the town added a new source and kept part of the old one. Choice A is the common error, because students assume the wells were shut down.
Answer: Accept any difference drawn from the table.
Examples include more people living in town, two tour boats now working from the dock, more water jobs, or water running all year instead of being shut off some afternoons.
Answer: 2,200 people.
3,600 minus 1,400 equals 2,200. Checking by addition, 1,400 plus 2,200 equals 3,600.
Answer: 24,000 gallons.
4,000 gallons each hour multiplied by 6 hours equals 24,000 gallons. Partial products give 4 times 6 equals 24, and 24 thousands is 24,000.
Answer: 120 minutes.
One hour is 60 minutes, so 2 hours is 60 times 2, which equals 120 minutes.
Answer: B.
The opening lines say the wells turned salty, and the table says water was shut off some afternoons in dry summers. Both point to a town that was running short.
Answer: Accept any real cost of the change, such as the energy the plant uses.
Students may name the money to build and run the plant, the energy needed to push sea water through the filters, the workers the town must pay, or the land the plant takes up along the shore.

Differentiation

Support

Give these students the table with the two numbers used in item 3 highlighted, and provide the subtraction already stacked in place value columns. For item 5, supply a small conversion card reading 1 hour equals 60 minutes, and let students skip count by 60 if that is easier than multiplying.

Extension

Ask students to add a third column headed Fifty Years From Now and to fill in two rows with a reasonable guess for the fictional town, then write one sentence explaining what would have to happen for their guess to come true. Students can also list which changes in the table were caused by the plant and which had other causes.

ELL supports

Preview the table headings aloud and pair each row label with a quick sketch, such as a well, a person, a boat, and a faucet. Provide sentence frames for items 2 and 7: "In 1970 the town had ___, and now the town has ___." and "One cost the town paid is ___."

Extensions

Have students find out where their own community's drinking water comes from, using the utility website or the yearly water quality report, and make a two-row then-and-now table if the source has changed. Students can compare their table with the fictional Corven Bay table and write one sentence about which town changed more.