Education Technology

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  • Subject Area

    • Math: Elementary Math: Algebraic Thinking
    • Math: Elementary Math: Measurement
    • Math: Elementary Math: Probability, Statistics and Data Analysis

  • Author

    Texas Instruments

  • Level

    K-5

  • Activity Time

    90 Minutes

  • Device
    • TI-15 Explorer™
  • Other Materials
      This is Activity 3 from the EXPLORATIONS Book:
      A World of Mathematics: Activities for Grades 4, 5, and 6 Using the TI-15

      The following materials are required for this activity:
    • Chart paper
    • Marker
    • Three 5-gallon aquariums
    • Sea salt
    • Warm water
    • Various objects to float
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How Salty Is It?

Published on 06/09/2008

Activity Overview

Students learn to solve a real-world problem involving salt water. Students will determine the amount of sea salt needed to turn an aquarium into a simulated salt-water environment. They also experiment with items and check their buoyancy in water with varying salt concentrations.

Before the Activity

  • See the attached PDF file for detailed instructions for this activity
  • Print pages 16 - 22 from the attached PDF file for your class
  • Review the four steps of problem solving with the students
  • During the Activity

    Distribute the pages to the class.

    Follow the activity procedures:

  • Read the problem statement
  • Use the given information to create a plan
  • Create a chart showing how much salt will be required to make each 5-gallon fish tank as salty as the ocean, Mono Lake, and Great Salt Lake
  • Set up the three 5-gallon fish tanks with calculated amounts of salt to simulate saltiness of the ocean, Mono Lake and Great Salt Lake
  • Test different items to find which items float, stay buoyant, or sink in the three tanks and record the results
  • Compare the results and write an explanation for the results


  • Converting volumes
  • Use the calculator to solve word problems involving the interconversion of ounces to liters and gallons to liters
  • After the Activity

  • Review student results
  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary