This activity promotes algebraic thinking of equivalency as well as giving children practice in addition and subtraction. Since there are many different solutions for the values of the unknowns, learners can focus on the idea of working systematically. Students see two weights on one side of an interactive balance, and are asked to find how many different ways they can hang three weights on the other side for it to be balanced. An easier problem, "Number Balance", (cataloged separately) is linked on the problem page. The Teachers' Notes page offers rationale, suggestions for implementation, discussion questions, ideas for extension and support.


  • Mathematics > General
  • Education > General

Education Levels:

  • Grade 1
  • Grade 2
  • Grade 3
  • Grade 4
  • Grade 5
  • Grade 6
  • Grade 7
  • Grade 8
  • Grade 9
  • Grade 10
  • Grade 11
  • Grade 12


Grade 2,Grade 3,Grade 1,NSDL,Addition,Early Elementary,Express regularity,Strategies,Number concepts,Social Sciences,Arithmetic,Analyze and persevere,Concept formation,Process skills,Number and operations,Visual representation,Algebra,Properties of operations,Critical thinking,Subtraction,Life Science,Composition and decomposition of numbers,oai:nsdl.org:2200/20140728161247608T,Informal Education,Whole numbers,NSDL_SetSpec_ncs-NSDL-COLLECTION-000-003-112-027,Comparison of numbers,Practice Standards,Elementary School,Reason quantitatively,Algebraic thinking,Chemistry,Operations,Mental calculation,Upper Elementary,Communication,Mathematical language,Mathematics,Connections,Equations,Problem solving,Education,Reasoning,Representation



Access Privileges:

Public - Available to anyone

License Deed:

Creative Commons Attribution Non-Commercial Share Alike


This resource has not yet been aligned.
Curriki Rating
'NR' - This resource has not been rated
'NR' - This resource has not been rated

This resource has not yet been reviewed.

Not Rated Yet.

Non-profit Tax ID # 203478467