This document provides instructions for converting percentages to decimals in 2 steps: 1) Remove the % sign 2) Move the decimal point two places to the left It then demonstrates this process for converting several percentages to decimals, such as 97% to 0.97, and explains that percentages and decimals represent equivalent values. Converting a percentage to a decimal simply involves multiplying the percentage by 100, which does not change the value.

1. % to Decimal

2. % to Decimal Just two steps. That’s all it takes.

3. This is the same exact thing as multiplying by 100. (x100) 1 st : Remove the % sign.

4. This is the exact same thing as dividing by 100. (÷ 100) 2 nd : Move the decimal two (2) places to the left.

5. Change 97% to decimal: 97% 1 st : 97 (take away % sign). 2 nd : .97 (move invisible decimal point behind the seven 2 places to the left in front of the 9). Final answer = .97

6. Change 461% to decimal: 461% 1 st : 461 (take away % sign) 2 nd : 4.61 (move invisible decimal point from behind the 1 two places to left so it is in between the 4 and the 6) Final answer = 4.61

7. Change 1350% to decimal: 1350% 1 st : 1350 (take away the % sign) 2 nd : 13.50 (move the invisible decimal point behind the 0 two places to the left so it is between the 3 and the 5). Final answer = 13.50 or 13.5

8. Change 7% to decimal: 7% 1 st : 7 (take away the % sign 2 nd : .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). Final answer = .07

9. Change .09% to decimal: .09% 1 st : .09 (Take away the % sign, but leave the decimal point where it is during this step.) 2 nd : .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. (1 original 0 & 2 new 0s) Final answer = .0009

10. Change .3468% to decimal: .3468% 1 st : .3468 (take away the % sign) 2 nd : .003468 (move the decimal place 2 places to the left. This creates 2 empty spaces. Fill them with 0.) Final answer = .003468

11. Change ½ % to decimal: New 1 st step: Change fraction to decimal first. ½ = .50 or .5 __.5___ 2) 1.0 So: ½ % = .50% 10 Now rewritten problem: 0 Change .50% to decimal:

12. Change .50 % to decimal: (Note: This is NOT (fifty) 50 %, it is (five tenths) 5/10 % or when the fraction five tenths is simplified (one half) ½ %) .50 % 1 st : .50 (take away the % sign) 2 nd : .0050 (move the decimal point 2 places to the left) Final answer = .0050 or .005

13. 2 ways to write the exact same numbers 97% is the exact same amount as .97 461% is the exact same as 4.61 1350% is the exact same number as 13.50 7% is the exact same as .07 .09% is the exact same amount as .0009 .3468% is the exact same as .003468 ½ % is identical to .5 % and .50% and .0050

14. % and decimals are equivalent Doing BOTH the 1 st step: Remove the % sign (x 100) and the 2 nd step: Move the decimal point two places to the left (÷ 100) is multiplying the percent by 1 or ( 100 ). (100)

15. Multiplying any number by 1 equals the exact same number you started with. So multiplying a percent by 100 equals the 100 exact same number and the exact same amount you started with, but the number is written as a decimal instead of a percent.

16. Congratulations Now you know how to change a number from a percent to a decimal by simply removing the % sign and moving the decimal point 2 places to the left.

17. Notes for teachers Correlates with Glencoe Mathematics Applications and Concepts : Course 1 Florida Edition (6 th grade) Chapter 10 Lesson 6 Glencoe Mathematics Applications and Concepts : Course 2 Florida Edition (7 th grade) Chapter 5 Lesson 6 Glencoe Mathematics Pre-Algebra Florida Edition (8 th grade) Chapter 6 Lesson 4 Photo credit: …alba… on www.flicker.com http://www.flickr.com/photos/bibba/2371962844/ PowerPoint created using Microsoft Office 2003 for Students and Teachers. For more information on my math class visit: http://walsh.edublogs.org