A Weighty Problem is a freely available elementary STEM+CT instructional unit developed by the Smithsonian Science Education Center with funding from the US Department of Defense STEM office. As part of the Smithsonian Science for Computational Thinking series, it is designed to address a bundle of science, engineering, mathematics, and computational thinking standards from the Next Generation Science Standards, the Common Core Mathematics Standards, the Computer Science Teachers Association Standards, and the ISTE student standards. In this unit, students:

  • Construct and revise an argument about the effect of mixing water and powder on the weight of the materials
  • Plan, write, debug, and conduct an investigation procedure about whether the weight of a powder disappears when it is mixed into water
  • Use patterns from a visual representation of class data as evidence to support a claim
  • Identify the important parts of the story about why and how they learned whether the weight of a powder disappears when it is mixed into water and create a storyboard using these story elements
  • Create and debug an animation that uses events, sequences, loops, and/or conditions to communicate how they learned that the weight of a powder does not disappear when mixed into water

Download the Teacher Guide

Below are additional resources that support teaching this unit.

Task 3: Writing the Investigation Procedure

Weighing Detailed Procedure
Download the Weighing Detailed Procedure PDF
This file gives an example of detailed procedure steps for weighing the drink container and powder tub.

Task 7: Revised Ideas

Lighten the Load

Cover of lighten the load reading with two images of soldiers and an image of a backpack
Download the Lighten the Load PDF
This file is an optional story that gives students insight into problems caused by carrying heavy loads and possible solutions.

Task 8: Sharing the Story—Storyboard

Animation Scenes
Download the Animation Scenes PDF
This file contains the sprites and backdrops that have been developed for students to use in their storytelling.

Task 9: Introduction to Computer Algorithms

Drink Mix Animation Scratch Project
This link provides an example of an animation created using Scratch. 

Drink Mix Animation Student Project
This link provides access to a starter project for student to use when creating their animations.

Drink Mix Animation Scratch Tutorial
Download the Drink Mix Animation Scratch Tutorial PDF

This file provides guidance in using the Scratch resources students will likely use in their animation programming.

A Weighty Problem Student Scratch Guide
Download the A Weighty Problem Student Scratch Guide PDF 
This file provides guidance for students using Scratch resources to create an animation.

Kit Tips & Tricks