Pan Balance

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What steps do you teach for a pan balance problem?

Below is an explanation of "math thinking" needed to solve for a pictorial variable. The passage is a good example of a "repeated reading" sample to build math vocabulary fluency.

Steps:

• 
  First, I looked at the balance to compare the numerals. I saw the squares were not congruent. They were not the same size even though they were the same shape.



• 
  The balance is the same as an equal mark. I can write a number sentence using the digits on the scale. They are the addend that will give an even sum.



• 
  On the right side of the scale, the addend 1 is odd. I know that the mystery number must be odd to make an even answer.



• 
  If I add the two numbers on the left, the total is 6. (2 + 4 = 6). The value of the right side must be the same! If I make a subtraction problem using the digits, it would be 6 – 1 = ____. So, the difference is 5!
  
  

Resources:

• http://homeschoolmath.blogspot.com/search/label/balance


• http://www.mathplayground.com/algebraic_reasoning.html


• http://www2.edc.org/mathpartners/pdfs/8-9%20Equations.pdfhttp://www.nsa.gov/teachers/ms/algrst39.pdf (problems for SMARTBoard)


• http://www.mathrealm.com/Units/Assignment_D.php?FileName=VariableMachine.dcr&UnitID=241 Understanding Function Words


• http://www.mathrealm.com/Units/Assignment_D.php?FileName=SolveOneVariableAddSub.dcr&UnitID=99 Solving for Variable on a Balance


• http://www.learner.org/channel/courses/learningmath/algebra/session6/part_c/index.html Bags, Blocks and Balance Lesson Activity


• http://www.mathsisfun.com/algebra/add-subtract-balance.html Flash Activity Add and Subtract on a Balance


• Software: http://www.exefind.com/balance-keeper-P3083.html Balance Keeper


• http://www.ciese.org/ciesemath/b3.html