Formulating Equations

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Formulating Equations

• K. Coleman
• Cobb 6th Grade Campus
• GPISD

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TEKS Objective 6.5

•   Patterns, relationships, and algebraic
  thinking. The student uses letters to represent
  an unknown in an equation. The student is
  expected to formulate an equation from a problem
  situation.

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Purpose

• develop the ability to collect data and record
  data in a table
• recognize what varies in an experiment
• name the independent and dependent variables in a
  problem

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Focus Activity 1

• The table below shows the relationship between
  the number of hours worked and the wages earned.
  What ratio describes this relationship?
• Hours 1 2 3 4
• Wages 8 16 24 32

Give a rule for this relationship
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Focus Activity 2

• The table below shows the relationship between
  the mileage and the fuel used in a new Ford
  Explorer. What ratio describes this relationship?
• Mileage 64 96 128 160
• Fuel (gal) 2 3 4 5

Give a rule for this relationship
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Instructions

• Use triangle and square pattern blocks to model
  houses
• Have students model House 1, 2, 3, and 4.
• Students should identify how many pieces it takes
  to model each house.
• Identify the ratio of triangles to squares,
  squares to triangles, and triangles to house
  number.
• Organize the data into a table.

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Instruction contd

• Determine a rule for your data.
• Use your rule to determine the number of pieces
  for House 5 and House 12
• Determine if the ratio is the same for house 5
  and house 12
• Identify any other rule you can determine from
  your data

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Guided Practice

• Julie is making cookies. It takes two cups of
  raisins for four dozen cookies. If she is making
  twenty four dozen cookies for the church fair,
  how many cups of raisins will she need?
• Paul uses 9 straws and 6 pieces of clay to make 1
  triangular prism. He uses 18 straws and 12 pieces
  of clay to make 2 triangular prisms. How many
  straws and pieces of clay will he need to make 5
  triangular prisms?
• Find a rule for each problem above.

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Independent Practice

• Students are to go to the following website

http//www.aaaknow.com/rat62ax2.htm
Perform the exercise on this website
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Conclusion

• You can use proportions to help solve a variety
  of situations

• In collecting data you can find a rule that
  applies to each situation. Use variables to
  identify your independent and dependent data

• Your rule should have at least one variable