Percent to Decimal

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How to change a percent to a decimal

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Percent to Decimal

  1. 1. % to Decimal
  2. 2. % to Decimal <ul><li>Just two steps. That’s all it takes. </li></ul>
  3. 3. <ul><li>This is the same exact thing as multiplying by 100. (x100) </li></ul>1 st : Remove the % sign.
  4. 4. <ul><li>This is the exact same thing as dividing by 100. (÷ 100) </li></ul>2 nd : Move the decimal two (2) places to the left.
  5. 5. <ul><li>Change 97% to decimal: </li></ul><ul><li>97% </li></ul><ul><li>1 st : </li></ul><ul><li>97 (take away % sign). </li></ul><ul><li>2 nd : </li></ul><ul><li>.97 (move invisible decimal point behind the seven 2 places to the left in front of the 9). </li></ul><ul><li>Final answer = .97 </li></ul>
  6. 6. <ul><li>Change 461% to decimal: </li></ul><ul><li>461% </li></ul><ul><li>1 st : </li></ul><ul><li>461 (take away % sign) </li></ul><ul><li>2 nd : </li></ul><ul><li>4.61 (move invisible decimal point from behind the 1 two places to left so it is in between the 4 and the 6) </li></ul><ul><li>Final answer = 4.61 </li></ul>
  7. 7. <ul><li>Change 1350% to decimal: </li></ul><ul><li>1350% </li></ul><ul><li>1 st : </li></ul><ul><li>1350 (take away the % sign) </li></ul><ul><li>2 nd : </li></ul><ul><li>13.50 (move the invisible decimal point behind the 0 two places to the left so it is between the 3 and the 5). </li></ul><ul><li>Final answer = 13.50 or 13.5 </li></ul>
  8. 8. <ul><li>Change 7% to decimal: </li></ul><ul><li>7% </li></ul><ul><li>1 st : </li></ul><ul><li>7 (take away the % sign </li></ul><ul><li>2 nd : </li></ul><ul><li>.07 (move the invisible decimal point behind the 7 two places to the left. Fill in the empty spot this made with a zero. The decimal place is now in front of the new 0). </li></ul><ul><li>Final answer = .07 </li></ul>
  9. 9. <ul><li>Change .09% to decimal: </li></ul><ul><li>.09% </li></ul><ul><li>1 st : </li></ul><ul><li>.09 (Take away the % sign, but leave the decimal point where it is during this step.) </li></ul><ul><li>2 nd : </li></ul><ul><li>.0009 (Move the decimal point from in front of the 0 two places to the left. This creates 2 empty spaces. Fill them with 2 new 0s. Now the decimal point is in front of 3 zeroes. </li></ul><ul><li>(1 original 0 & 2 new 0s) </li></ul><ul><li>Final answer = .0009 </li></ul>
  10. 10. <ul><li>Change .3468% to decimal: </li></ul><ul><li>.3468% </li></ul><ul><li>1 st : </li></ul><ul><li>.3468 (take away the % sign) </li></ul><ul><li>2 nd : </li></ul><ul><li>.003468 (move the decimal place 2 places to the left. This creates 2 empty spaces. Fill them with 0.) </li></ul><ul><li>Final answer = .003468 </li></ul>
  11. 11. <ul><li>Change ½ % to decimal: </li></ul><ul><li>New 1 st step: </li></ul><ul><li>Change fraction to decimal first. </li></ul><ul><li>½ = .50 or .5 __.5___ </li></ul><ul><li>2) 1.0 </li></ul><ul><li>So: ½ % = .50% 10 </li></ul><ul><li>Now rewritten problem: 0 </li></ul><ul><li>Change .50% to decimal: </li></ul>
  12. 12. <ul><li>Change .50 % to decimal: </li></ul><ul><li>(Note: This is NOT (fifty) 50 %, it is (five tenths) 5/10 % </li></ul><ul><li>or when the fraction five tenths is simplified </li></ul><ul><li>(one half) ½ %) </li></ul><ul><li>.50 % </li></ul><ul><li>1 st : </li></ul><ul><li>.50 (take away the % sign) </li></ul><ul><li>2 nd : </li></ul><ul><li>.0050 (move the decimal point 2 places to the left) </li></ul><ul><li>Final answer = .0050 or .005 </li></ul>
  13. 13. 2 ways to write the exact same numbers <ul><li>97% is the exact same amount as .97 </li></ul><ul><li>461% is the exact same as 4.61 </li></ul><ul><li>1350% is the exact same number as 13.50 </li></ul><ul><li>7% is the exact same as .07 </li></ul><ul><li>.09% is the exact same amount as .0009 </li></ul><ul><li>.3468% is the exact same as .003468 </li></ul><ul><li>½ % is identical to .5 % and .50% and .0050 </li></ul>
  14. 14. % and decimals are equivalent <ul><li>Doing BOTH the </li></ul><ul><li>1 st step: Remove the % sign (x 100) </li></ul><ul><li>and the </li></ul><ul><li>2 nd step: Move the decimal point two places to the left (÷ 100) </li></ul><ul><li>is multiplying the percent by 1 or ( 100 ). </li></ul><ul><li> (100) </li></ul>
  15. 15. <ul><li>Multiplying any number by 1 equals the exact same number you started with. </li></ul><ul><li>So multiplying a percent by 100 equals the </li></ul><ul><li>100 </li></ul><ul><li>exact same number and the exact same amount you started with, </li></ul><ul><li>but the number is </li></ul><ul><li>written as a decimal instead of a percent. </li></ul>
  16. 16. Congratulations <ul><li>Now you know how to change a number from a percent to a decimal </li></ul><ul><li>by simply </li></ul><ul><li>removing the % sign </li></ul><ul><li>and </li></ul><ul><li>moving the decimal point 2 places to the left. </li></ul>
  17. 17. Notes for teachers <ul><li>Correlates with Glencoe Mathematics Applications and Concepts : Course 1 Florida Edition (6 th grade) Chapter 10 Lesson 6 </li></ul><ul><li>Glencoe Mathematics Applications and Concepts : Course 2 Florida Edition (7 th grade) Chapter 5 Lesson 6 </li></ul><ul><li>Glencoe Mathematics Pre-Algebra Florida Edition (8 th grade) Chapter 6 Lesson 4 </li></ul><ul><li>Photo credit: …alba… on www.flicker.com </li></ul><ul><li>http://www.flickr.com/photos/bibba/2371962844/ </li></ul><ul><li>PowerPoint created using Microsoft Office 2003 for Students and Teachers. </li></ul><ul><li>For more information on my math class visit: http://walsh.edublogs.org </li></ul>

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