1 / 26

Bell Work:

Bell Work: If 479 stocks advanced in price and 326 declined in price, then what was the approximate ratio of advancers to decliners?. Answer: 5 to 3. Lesson 30: Repeating Decimals.

herlinda
Download Presentation

Bell Work:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Bell Work: If 479 stocks advanced in price and 326 declined in price, then what was the approximate ratio of advancers to decliners?

  2. Answer: 5 to 3

  3. Lesson 30:Repeating Decimals

  4. Recall that to express a ratio as a decimal number, we perform the division indicated. For example, to convert ¾ to a decimal number, we divide 3 by 4. 3 ÷ 4 = 0.75

  5. Notice that we use a decimal point and zeros to write 3 as 3.00 so that we could perform the division. Some fractions convert to decimal numbers that have repeating digits such as 0.272727…..

  6. ____ Repetend*: name given to the repeating decimals We indicate repeating digits with a bar over the repetend. We write 0.2727272727… as 0.27.

  7. Example: Express the fraction as a decimal number. 1/6

  8. __ Answer: 0.166 6Γ1.000 6 40 36 40 36 4 = 0.16

  9. Example: Express the mixed number as a decimal number. 2 1/3

  10. ___ Answer: The mixed number 2 1/3 is a whole number plus a fraction. The whole number is 2 and the fraction 1/3 converts to 0.333… = 2.3

  11. Recall that converting a rational number to a decimal form has three possible outcomes. The rational number is an integer The rational number is a terminating decimal number The rational number is a non-terminating decimal with repeating digits

  12. Non-terminating, non-repeating decimal numbers are irrational and do not result from converting a rational number to a decimal number. To perform calculations with repeating decimals we first round the number to a suitable number of decimal places.

  13. Example: Find 5/6 of $12.47.

  14. __ Answer: 5/6 = 0.83 0.83 x 12.47 = 10.3501 $10.35

  15. __ Example: Arrange in order from least to greatest. 0.3, 0.3, 0.33

  16. __ __ Answer: 0.3 = 0.300 0.3 = 0.333 0.33 = 0.330 0.3, 0.33, 0.3

  17. Many calculators do not have functions that enable the user to perform arithmetic with fractions. To convert a fraction to a decimal, we enter the numerator, press the ÷ key, then key in the denominator and press =.

  18. Convert these fractions to decimals. 10/11 11/12 17/80

  19. ____ __ Answer: 10/11 = 0.90 11/12 = 0.916 17/80 = 0.2125

  20. To add fractions it is not necessary to enter long repeating decimals and it is not necessary to round the decimal equivalents. For example, to add 5/6 and 8/3 on a calculator that has algebraic logic (follows the order of operations), we can use this key stroke sequence: 5 ÷ 6 + 8 ÷ 3 = If your calculator has algebraic logic, the final display should read 3.5 which equals 3 ½.

  21. Try these operations and write the answer in decimal form. 11/12 + 11/6 17/24 – ½

  22. __ Answer: 11/12 + 11/6 = 2.75 17/24 – ½ = 0.2083

  23. Many calculators do not have a percent key. To find a given percent of a number with a calculator, we mentally shift the decimal point two places to the left before we enter the number.

  24. Estimate 6.25% of $72.59. then use a calculator to perform the actual calculation and round the answer to the nearest cent. What decimal number did you enter for 6.25%?

  25. Answer: About $4.20 rounds to $4.54 Enter .0625

  26. HW: Lesson 30 #1-30 Due Tomorrow

More Related