Lesson 94 Notes

 

Expressions:

An algebraic expression ALWAYS contains a variable.  (Example of variable:  x, n, - any letter).  A variable is the unknown. 

 

Complete the Word Phrase - 15 + 32  = 32 added to 15

6c = 6 times c

8x -2 =  2 less than 8x

A number divided by 7 =  n

 

 

 

  • Add: sum, addition, more than, increased by, greater, plus, total

  • Subtract: decreased by, less, less than, subtract, difference, diminished by, reduced, minus

  • Multiply: times, product of, percent of, twice, doubled

  • Divide: quotient, divided by, per, quantity

  • Equals: is, was, equals, will be, results in

  • Percent Symbol:  %

  • Multiply Symbol:   3x3         3(3)           3•3

  • Division Symbol:    ÷   /

  • Greater Than:  >

  • Less Than:  <

 

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          Percent to Decimal- Move decimal point two (2) places to the left.  Example (1.5%  to 0.015)  (57% to .57)

          Decimal to percent – Move decimal point two (2) places to the right.  Example (.015 to 1.5%)  (.57 to 57%)

 

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SALES TAX

To find what the dollar ($) amount of a sales tax when given the percent: 

          Step 1: Convert the percent to a decimal.  Example 6% would change to 0.06. 

          Step 2: Now take the cost of the item and multiply it by 0.06 (the sales tax). 

                           Say the item cost $25.00, put in your calculator $25 x .06 =$ 1.50

          Step 3:  Now we need to know how much we must give to the sales clerk for the item plus the sales tax.  We need to add the                                 price of the item ($25.00 plus the sales tax (1.50).

                           $25.00 + 1.50 = $26.50

                          You will hand the sales clerk $26.50.

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PROPORTIONS AND PERCENTS

 

Word form:               The ratio comparing the part to the whole is equivalent to the ratio comparing the percent to 100.

Equation form:     

Part    =      x    
Whole     100

 

USE PROPORTIONS FOR FINDING A MISSING PART -  

Example:           7        =         X    
                               20                60

                                20x = 420     (crisscross multiply)   20 x X    and 7 x 60)
                                      x = 21