BUILDING FORMULAS

 

GOALS

1.      Represent a visual pattern with words, symbols, and numbers.

2.      Describe visual patterns using recursive and direct formulas.

3.      Generate and use a table of values and/or graph.

4.      Use and construct recursive and direct formulas.

5.      Square and find the square root of a number.

6.      Understand the distributive property.

7.      Recognize the advantages & disadvantages of different representations (tables, direct & recursive formulas, and visual models).

8.      Understand the inverse relationship between square and square root.

9.      Recognize equivalent representations for the same situation.

10.  Appreciate the usefulness of formulas.

11.  Use formulas to solve simple problems.

12.  Generalize a particular situation by means of a general formula.

 

SECTION SUMMARIES

 

SECTION A: PATTERNS

1.       You can leave out the “x” when multiplying.  T=4xL-1 is the same as T=4L-1.

2.       When adding or multiplying, you can change the order.  T=(P+1)x3+2 is the same as T=3(P+1)+2.

 

SECTION B: BASIC PATTERNS

1.       If you have to repeat a calculation over and over, using a formula can be helpful.

2.       A formula with parenthesis can be written without parenthesis. 2(4S+3L) is the same as 8S+6L

3.       A formula without parenthesis can be written with parenthesis. 6S+3L is the same as 3(2S+1L)

 

SECTION C:  AREA

1.        A number is a perfect square if its square root is a whole number.

2.        Unsquaring allows you to find the length of a side of a square if you know the square’s area.  It also allows you to find the radius of a circle whose area is known.

 

SECTION D:  FORMULAS…Can be used to:

1.       describe a situation, as was the case with the Egyptian art, for which formulas describe how drawings were made.

2.       solve problems, such as how to convert temperatures.

3.       investigate possibilities within certain constraints, such as staircases.

4.       Information in formulas can also be given in pictures, stories, graphs, tables, or other formulas.

5.       When solving problems, be sure to choose the best way to organize and represent the information.