Using Formulas to Solve Problems

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Using Formulas to Solve Problems. LG: I can solve real-world problems by substituting values into formulas and solving. INVESTIGATION. These formulas give the height, h , of an adult. - PowerPoint PPT Presentation

Text of Using Formulas to Solve Problems

Box 2: Using Formulas to Solve Problems

Using Formulas to Solve ProblemsLG: I can solve real-world problems by substituting values into formulas and solving.INVESTIGATIONThese formulas give the height, h, of an adult.They rely on the lengths of the radius bone, r, and the femur bone, f. (Note: All measurements are in centimeters)

A) predict the height of a female whose femur is 40.6 cm longMALEFEMALEUsing the radius boneh = 3.65 r + 80.41h = 3.88 r + 73.50Using the femur boneh = 2.24 f + 69.09h = 2.32 f + 61.41INVESTIGATIONThese formulas give the height, h, of an adult.They rely on the lengths of the radius bone, r, and the femur bone, f.

B) predict the height of a male whose radius is 28.1 cm long.MALEFEMALEUsing the radius boneh = 3.65 r + 80.41h = 3.88 r + 73.50Using the femur boneh = 2.24 f + 69.09h = 2.32 f + 61.41INVESTIGATIONThese formulas give the height, h, of an adult.They rely on the lengths of the radius bone, r, and the femur bone, f.

C) Complete the chart

D) Which formula gave you the more accurate prediction?

MALEFEMALEUsing the radius boneh = 3.65 r + 80.41h = 3.88 r + 73.50Using the femur boneh = 2.24 f + 69.09h = 2.32 f + 61.41Length of yoursCalculation of your heightActual heightRadiusFemurWhat is a formula?Its a mathematical equation that relates two or more variables, which each represent real-world quantities.

Can you think of any examples from work or school?Example 1 Substituting into a formulaPediatric nurses use Youngs formula,to calculate a childs dose of medicine.C is the childs dose in milligramsA is the adults dose in milligramsg is the childs age in years. If the adult dose of a medication is 600 mg, what would be a 3-year-olds dose?

Example 2 Choosing Formulas and Converting MeasuresA landscaper uses a bucket with radius 18 cm and height 18 cm to pour soil into a rectangular planter that measures 1 m by 40 cm by 20 cm. How many buckets of soil are needed to fill the planter?OUR PLAN:Investigation: How much do I need to eat?What is a BMR?Used to determine the amount of energy required by the body at rest. This value can then be adjusted depending on activity level

Use the Harris-Benedict Equation to calculate your BMR

You will need: Age in yearsWeight in kg (pounds x 2.2)Height in cm (measuring tapes available)Rearranging FormulasLG: I can rearrange a formula by undoing each operation

LG: I can solve problems using rearranged formulasMINDS ONTo change a flat tire, FIRST, you have to take the old tire off, THEN, you have to put the new tire on.The process of removing the old tire is shown below.Put the new tire on by undoing each operation you completed to take the old tire off.

Applying this undoing to math

Example 1a Isolating a Variable

Example 1b Isolating a Variable

Example 1c Isolating a Variable

Example 2

When should we do what?ISOLATE the variable THEN SUBSTITUTE in given valuesIf you have to solve for the variable several timesSUBSTITUTE in given values THEN SOLVE for the variableIf the numbers are simpleIf rearranging the formula is really difficultExample 3a Solving problems with Powers

Example 3a Solving problems with Powers

Quiz tomorrow!On these learning goals:I can solve real-world problems by substituting values into formulas and solving.

I can rearrange a formula by undoing each operation.

I can solve problems using rearranged formulas.