PERCENTS
                                                                LESSON 2




                                                                      TENNESSEE
                                                                   ADULT EDUCATION




This curriculum was written with funding of the Tennessee Department of Labor and Workforce Development and may not be reproduced in any way without written permission. Š
WHAT IS PERCENT?

It’s the number of parts out of 100.


25% means 25 parts out of 100
WHEN SOLVING PERCENT PROBLEMS, YOU WILL BE
SOLVING FOR ONE OF THESE THREE PARTS.


    E

           Percent   Whole Part
25% OF THE PIZZA

Does 25% = 25?

No.

There are not 25 pizzas.

25% is 25 slices out of 100 total.
BEFORE SOLVING PERCENT PROBLEMS, IT IS
NECESSARY TO CHANGE THE PERCENT TO A
DECIMAL.
 When given the percent, always move the decimal 2
  places to the left.

   For example: 13% = .13
                                 Tenths
                         Ones
                                      Hundredths
                     Tens                Thousandths
              Hundreds


                    000 130      .
                                decimal
Let’s practice changing the following percents to decimals.

1. 62% = _____      2. 122% = _____             3. 2% = _____
AT THE END OF PROBLEMS, YOU MAY NEED TO
CHANGE FROM A DECIMAL BACK INTO A PERCENT.
 When you have a decimal, always move the decimal 2
  places to the right to make a percent.

   For example: .6 = 60%
                                 Tenths
                         Ones
                                      Hundredths
                     Tens                Thousandths
              Hundreds


                    000 600      .
                                decimal
Let’s practice changing the following percents to decimals.

1. .33 = _____      2. .6 = _____               3. .03 = _____
WHEN SOLVING PERCENT PROBLEMS, YOU WILL BE
SOLVING FOR ONE OF THESE THREE PARTS.


    Example: 25% of 200 is 50.

            Percent   Whole Part
One way to solve percent problems is to use the Percent
Pyramid. The pyramid will explain what operation is
necessary to solve the problem.




                                      In other words:
               Part                   •When given the PART,
                                      you must divide.
                 á
                                      •When given the
                                      WHOLE and the
       Whole     X    Percent         PERCENT, you must
                                      multiply.
The following charts provide key words that will
help identify what each number represents in a
word problem.

      Whole                            Part
 F                          Follows the word “is”
                            Discounted Price
                            Interest
                            Down Payment
                            Amount Paid
                            Taxes
                            Tips
GUIDED PRACTICE
Example: 25% of 200 is 50.

       Percent     Whole   Part

                                          Part
 What is 20% of 30?

                                          á

                                          X
      Percent    Whole
                                  Whole          Percent


 .2 X 30 =
GUIDED PRACTICE
Example: 25% of 200 is 50.

       Percent     Whole   Part

                                          Part
 What is 40% of 300?

                                          á

                                          X
      Percent    Whole
                                  Whole          Percent


 .4 X 300 =
GUIDED PRACTICE
Example: 25% of 200 is 50.

       Percent     Whole   Part

                                          Part
 What is 25% of 300?

                                          á

                                          X
      Percent    Whole
                                  Whole          Percent


 .25 X 300 =
GUIDED PRACTICE
Example: 25% of 200 is 50.

       Percent    Whole   Part

                                         Part
 What % of 300 is 30?

                                         á

                                         X
          Whole   Part
                                 Whole          Percent


30 á 300 =
GUIDED PRACTICE
Example: 25% of 200 is 50.

       Percent    Whole   Part

                                         Part
 What % of 100 is 50?

                                         á

                                         X
          Whole   Part
                                 Whole          Percent


50 á 100 =
GUIDED PRACTICE
Example: 25% of 200 is 50.

       Percent     Whole      Part

                                             Part
 20 is what percent of 100.

                                             á

                                             X
Part                 Whole
                                     Whole          Percent


20 á 100 =
GUIDED PRACTICE
Directions: Solve each problem using the Percent Pyramid.
Draw out the pyramid for each problem.

1.30% of 90 = ______

2.25% of 180 = ______                   Part

3.What % of 30 is 6?

4.$12 is what percent of $48?            á
5.14 is 20% of what number?
                                         X
6.20% of what number is 34?     Whole          Percent
GUIDED PRACTICE
Directions: Solve each problem using the Percent Pyramid.
Draw out the pyramid for each problem.

1.30% of 90 = __27__

2.25% of 180 = __45__                          Part

3.What % of 30 is 6? 20%

4.$12 is what percent of $48? 25%              á
5.14 is 20% of what number? 70
                                               X
6.20% of what number is 34?      170   Whole          Percent
STEPS FOR SOLVING PERCENT WORD
PROBLEMS.

 1. Read the problem.
 2. Determine what the numbers represent.
  a. Is the number the: Part, Whole, or Percent
  b. This will also help determine what the problem wants
     to know.
 3. Using the percent pyramid, determine what
    operation is necessary to solve the problem.
 4. Solve.
 5. Ask, “Does this answer make sense?”
  There may be another step. BE CAREFUL!
STEP 1: READ THE PROBLEM.

When Meyer bought a new stove, he made a
$146 down payment. If the down payment is
25% of the purchase price, what is the cost
of the stove?
Step 2: Determine what the numbers represent.

When Meyer bought a new stove, he made a $146 down
payment. If the down payment is 25% of the purchase price,
what is the cost of the stove?


Look back at the key words provided earlier in the PowerPoint.
             What does down payment represent?
                             The Part
•$146 is a down payment, therefore, it is only PART of the
purchase price and will be placed in the top section of the pyramid.


•25 is the percent because it has the % sign; the percent is placed
in the bottom right corner of the pyramid.
Step 3: Draw the percent pyramid, and fill it in.



 •   $146 was the part.


 • The percent was also given.                         part
     25%
                                                       $146

 The pyramid indicates                                  á
 division is the operation
 needed to solve the                                    X      25%
 problem.
                                              whole           percent

         HINT: Don’t forget to change the percent to a decimal!
STEP 4 : SOLVING THE PROBLEM

Set up the division:
                           .25 146
Change the decimal
to a whole number by
moving the decimal              If you change the outside
back to the right.              number, you have to move
                                the inside number the same
                                number of spaces. Then add
                                zeros to cover the empty
                                spaces.
Looks like:    25 14600.
STEP 4: SOLVING PROBLEM
 Divide:
           4       5 84
           2
           25 $14600.
               - 125
                   21 0
                 - 200
                    10 0
                    100
                      0
STEP 5: READ THE PROBLEM AGAIN.
When Meyer bought a new stove, he made a $146 down
payment. If the down payment is 25% of the purchase price,
what is the cost of the stove?

 What does the question want to know?


               The price of the stove.

        Is $584 a reasonable price for a stove?


                          YES
Guided Practice:
Our meal was $39.50, but we got a 20% discount
because our food was late. What did our meal cost after
the discount?

Step 1: Read the problem!
Step 2: Determine what the numbers stand for.
            $39.50 was the total cost = whole
            20 % = is the percent
Step 3: Draw and fill in the
triangle.


               ?
                               Notice that you have both
                               numbers on the bottom of
                               the triangle. When this
       $39.50 20%              happens, you simply
                               multiply.
STEP 4: SOLVE THE PROBLEM.
Hint: When solving by hand, you must change the
percent to a decimal by moving the decimal two places
to the left.
            $39.50
            x .20
            7.9000
* Count the number of decimal places in the problem
and move the decimal that many places.
STEP 5: DOES THE ANSWER MAKE SENSE?

Always make sure you answered the question.
    • Is $7.90 a reasonable answer.
    • No, if you were given a 20% discount, $7.90 is more
      than half off the price. This does not make sense.


You must subtract the $7.90 from the original cost to find
what you will pay for the meal.
                    $39.50
                     - 7.90
                    $31.60 is the amount paid.
1. During the November special election in Blaine, only 15,400
   voters went to the ballot box. If 44,000 registered voters live in
   Blaine, what percent of the registered voters cast their votes?

Step 2: 15,400 is part of the voters; 44,000 is the total number of voters which
makes it the whole.

Step 3: Use the pyramid to determine what operation to use.

                                                                  ¡35
                                     Step 4:   44,000   )   15400.00
                                                            13200 0
                                                             2200 00
              15400                                          2200 00


                                               HINT: Don’t forget to
       44,000           ?                      change the decimal to a
                                               percent.
                                                                 35%
2. Julia had her car windshield replaced at a cost of $250. After a
$25 deductible is applied, her insurance company will pay 80
percent of the remaining balance. In dollars, how much will the
insurance company pay?
Step 2: $250 is the total cost; $25 is the deductible; and 80 is the percent the
insurance company will pay. Be careful! $250 is not the whole because the 80 is
the percent off the remaining balance after the deductible; therefore, the $250 is
extra information. Find the whole by subtracting the deductible.

          $250 – $25 = $225          Step 3: Fill out pyramid.
                                     Step 4: Solve.



               $180                                       $225
                                                          x .80
                                                          18000
        $225          80 %                            Don’t forget the
                                                      decimal. There are 2
                                                      decimal places.
3. Mr. and Mrs. Potato Head bought a house five years ago for
    95,000. Since then, the value of their home has increased
    2%. In dollars, what is the value of their home now?

Step 2: 95,000 is the original amount; 2 is the percent.
Step 3: Fill out pyramid.

Step 4: Solve.

         95,000
                     Step 5: Does $1900.00 make sense
         x .02
                     for the price of a home?
        1900.00
                     No, Add the increase back to the
                     original cost of the home.                     1,900

            95,000
            +1,900                                         95,000           2%
           $96,900
4. Mr. Buzz took Mr. Woody out for dinner. The cost of their
 meal was $32.00. If Mr. Buzz wishes to leave a 15% tip,
 how much money should he leave for a tip?

Step 2: $32.00 is the original amount; 15 is the percent off the original amount.
Step 3: Fill out pyramid.

Step 4: Solve.

             $32
            x.15
             160
             320                                                $4.80
                            HINT: Don’t forget
             480            the decimal.

  Step 5: Is $4.80 a reasonable                           $32.00       15%
  amount to leave for a tip? YES

2 Percents

  • 1.
    PERCENTS LESSON 2 TENNESSEE ADULT EDUCATION This curriculum was written with funding of the Tennessee Department of Labor and Workforce Development and may not be reproduced in any way without written permission. Š
  • 2.
    WHAT IS PERCENT? It’sthe number of parts out of 100. 25% means 25 parts out of 100
  • 3.
    WHEN SOLVING PERCENTPROBLEMS, YOU WILL BE SOLVING FOR ONE OF THESE THREE PARTS. E Percent Whole Part
  • 4.
    25% OF THEPIZZA Does 25% = 25? No. There are not 25 pizzas. 25% is 25 slices out of 100 total.
  • 5.
    BEFORE SOLVING PERCENTPROBLEMS, IT IS NECESSARY TO CHANGE THE PERCENT TO A DECIMAL.  When given the percent, always move the decimal 2 places to the left. For example: 13% = .13 Tenths Ones Hundredths Tens Thousandths Hundreds 000 130 . decimal Let’s practice changing the following percents to decimals. 1. 62% = _____ 2. 122% = _____ 3. 2% = _____
  • 6.
    AT THE ENDOF PROBLEMS, YOU MAY NEED TO CHANGE FROM A DECIMAL BACK INTO A PERCENT.  When you have a decimal, always move the decimal 2 places to the right to make a percent. For example: .6 = 60% Tenths Ones Hundredths Tens Thousandths Hundreds 000 600 . decimal Let’s practice changing the following percents to decimals. 1. .33 = _____ 2. .6 = _____ 3. .03 = _____
  • 7.
    WHEN SOLVING PERCENTPROBLEMS, YOU WILL BE SOLVING FOR ONE OF THESE THREE PARTS. Example: 25% of 200 is 50. Percent Whole Part
  • 8.
    One way tosolve percent problems is to use the Percent Pyramid. The pyramid will explain what operation is necessary to solve the problem. In other words: Part •When given the PART, you must divide. ÷ •When given the WHOLE and the Whole X Percent PERCENT, you must multiply.
  • 9.
    The following chartsprovide key words that will help identify what each number represents in a word problem. Whole Part F Follows the word “is” Discounted Price Interest Down Payment Amount Paid Taxes Tips
  • 10.
    GUIDED PRACTICE Example: 25%of 200 is 50. Percent Whole Part Part What is 20% of 30? á X Percent Whole Whole Percent .2 X 30 =
  • 11.
    GUIDED PRACTICE Example: 25%of 200 is 50. Percent Whole Part Part What is 40% of 300? á X Percent Whole Whole Percent .4 X 300 =
  • 12.
    GUIDED PRACTICE Example: 25%of 200 is 50. Percent Whole Part Part What is 25% of 300? á X Percent Whole Whole Percent .25 X 300 =
  • 13.
    GUIDED PRACTICE Example: 25%of 200 is 50. Percent Whole Part Part What % of 300 is 30? á X Whole Part Whole Percent 30 á 300 =
  • 14.
    GUIDED PRACTICE Example: 25%of 200 is 50. Percent Whole Part Part What % of 100 is 50? á X Whole Part Whole Percent 50 á 100 =
  • 15.
    GUIDED PRACTICE Example: 25%of 200 is 50. Percent Whole Part Part 20 is what percent of 100. á X Part Whole Whole Percent 20 á 100 =
  • 16.
    GUIDED PRACTICE Directions: Solveeach problem using the Percent Pyramid. Draw out the pyramid for each problem. 1.30% of 90 = ______ 2.25% of 180 = ______ Part 3.What % of 30 is 6? 4.$12 is what percent of $48? á 5.14 is 20% of what number? X 6.20% of what number is 34? Whole Percent
  • 17.
    GUIDED PRACTICE Directions: Solveeach problem using the Percent Pyramid. Draw out the pyramid for each problem. 1.30% of 90 = __27__ 2.25% of 180 = __45__ Part 3.What % of 30 is 6? 20% 4.$12 is what percent of $48? 25% á 5.14 is 20% of what number? 70 X 6.20% of what number is 34? 170 Whole Percent
  • 18.
    STEPS FOR SOLVINGPERCENT WORD PROBLEMS. 1. Read the problem. 2. Determine what the numbers represent. a. Is the number the: Part, Whole, or Percent b. This will also help determine what the problem wants to know. 3. Using the percent pyramid, determine what operation is necessary to solve the problem. 4. Solve. 5. Ask, “Does this answer make sense?” There may be another step. BE CAREFUL!
  • 19.
    STEP 1: READTHE PROBLEM. When Meyer bought a new stove, he made a $146 down payment. If the down payment is 25% of the purchase price, what is the cost of the stove?
  • 20.
    Step 2: Determinewhat the numbers represent. When Meyer bought a new stove, he made a $146 down payment. If the down payment is 25% of the purchase price, what is the cost of the stove? Look back at the key words provided earlier in the PowerPoint. What does down payment represent? The Part •$146 is a down payment, therefore, it is only PART of the purchase price and will be placed in the top section of the pyramid. •25 is the percent because it has the % sign; the percent is placed in the bottom right corner of the pyramid.
  • 21.
    Step 3: Drawthe percent pyramid, and fill it in. • $146 was the part. • The percent was also given. part 25% $146 The pyramid indicates ÷ division is the operation needed to solve the X 25% problem. whole percent HINT: Don’t forget to change the percent to a decimal!
  • 22.
    STEP 4 :SOLVING THE PROBLEM Set up the division: .25 146 Change the decimal to a whole number by moving the decimal If you change the outside back to the right. number, you have to move the inside number the same number of spaces. Then add zeros to cover the empty spaces. Looks like: 25 14600.
  • 23.
    STEP 4: SOLVINGPROBLEM Divide: 4 5 84 2 25 $14600. - 125 21 0 - 200 10 0 100 0
  • 24.
    STEP 5: READTHE PROBLEM AGAIN. When Meyer bought a new stove, he made a $146 down payment. If the down payment is 25% of the purchase price, what is the cost of the stove? What does the question want to know? The price of the stove. Is $584 a reasonable price for a stove? YES
  • 25.
    Guided Practice: Our mealwas $39.50, but we got a 20% discount because our food was late. What did our meal cost after the discount? Step 1: Read the problem! Step 2: Determine what the numbers stand for. $39.50 was the total cost = whole 20 % = is the percent
  • 26.
    Step 3: Drawand fill in the triangle. ? Notice that you have both numbers on the bottom of the triangle. When this $39.50 20% happens, you simply multiply.
  • 27.
    STEP 4: SOLVETHE PROBLEM. Hint: When solving by hand, you must change the percent to a decimal by moving the decimal two places to the left. $39.50 x .20 7.9000 * Count the number of decimal places in the problem and move the decimal that many places.
  • 28.
    STEP 5: DOESTHE ANSWER MAKE SENSE? Always make sure you answered the question. • Is $7.90 a reasonable answer. • No, if you were given a 20% discount, $7.90 is more than half off the price. This does not make sense. You must subtract the $7.90 from the original cost to find what you will pay for the meal. $39.50 - 7.90 $31.60 is the amount paid.
  • 29.
    1. During theNovember special election in Blaine, only 15,400 voters went to the ballot box. If 44,000 registered voters live in Blaine, what percent of the registered voters cast their votes? Step 2: 15,400 is part of the voters; 44,000 is the total number of voters which makes it the whole. Step 3: Use the pyramid to determine what operation to use. ·35 Step 4: 44,000 ) 15400.00 13200 0 2200 00 15400 2200 00 HINT: Don’t forget to 44,000 ? change the decimal to a percent. 35%
  • 30.
    2. Julia hadher car windshield replaced at a cost of $250. After a $25 deductible is applied, her insurance company will pay 80 percent of the remaining balance. In dollars, how much will the insurance company pay? Step 2: $250 is the total cost; $25 is the deductible; and 80 is the percent the insurance company will pay. Be careful! $250 is not the whole because the 80 is the percent off the remaining balance after the deductible; therefore, the $250 is extra information. Find the whole by subtracting the deductible. $250 – $25 = $225 Step 3: Fill out pyramid. Step 4: Solve. $180 $225 x .80 18000 $225 80 % Don’t forget the decimal. There are 2 decimal places.
  • 31.
    3. Mr. andMrs. Potato Head bought a house five years ago for 95,000. Since then, the value of their home has increased 2%. In dollars, what is the value of their home now? Step 2: 95,000 is the original amount; 2 is the percent. Step 3: Fill out pyramid. Step 4: Solve. 95,000 Step 5: Does $1900.00 make sense x .02 for the price of a home? 1900.00 No, Add the increase back to the original cost of the home. 1,900 95,000 +1,900 95,000 2% $96,900
  • 32.
    4. Mr. Buzztook Mr. Woody out for dinner. The cost of their meal was $32.00. If Mr. Buzz wishes to leave a 15% tip, how much money should he leave for a tip? Step 2: $32.00 is the original amount; 15 is the percent off the original amount. Step 3: Fill out pyramid. Step 4: Solve. $32 x.15 160 320 $4.80 HINT: Don’t forget 480 the decimal. Step 5: Is $4.80 a reasonable $32.00 15% amount to leave for a tip? YES