Transcript 10 Rounding
Year 7 mathematics: Decimals 6-Apr-16 Rounding To round off to a decimal: 1. Check how many decimal places you need to round the answer to. a. The question may ask for 1, 2 etc decimal places. b. The question may ask for the nearest tenth, hundredth, etc. 2. Find this decimal place. 3. Look at the number in the next decimal place: a. If the number is 0, 1, 2, 3 or 4: Write the original number to the decimal place required. Leave off all other numbers. b. If the number is 5, 6, 7, 8 or 9 Write the original number to the decimal place required. BUT make the last digit 1 bigger. Year 7 mathematics: Decimals Example 1 Round the following to the number of places indicated. a) 5·456 (1) 5·5 b) 7·38499 (2) 7·38 c) 8·01950001 (3) 8·020 Example 2 Round the following to the number of places indicated. a) 0·2499 (tenth) 0·2 b) 7·9998 (thousandth) 8·000 1·71 c) 1·714895 (hundredth) 6-Apr-16 Year 7 mathematics: Decimals 6-Apr-16 Rounding Decimals Round of the following to 2 decimal places 12.347 = 12.35 What are the two options for our answer? 12.34 12.345 Where does Which is itit lie? to? closer 12.35 What decimal is right in the middle? Year 7 mathematics: Decimals 6-Apr-16 Rounding Decimals Round of the following to 2 decimal places 0.562 = 0.56 What are the two options for our answer? 0.56 0.565 Where does Which is itit lie? to? closer 0.57 What decimal is right in the middle? Year 7 mathematics: Decimals 6-Apr-16 Rounding Decimals Round of the following to 2 decimal places 0.499 = 0.50 What are the two options for our answer? 0.49 0.495 Where does Which is itit lie? to? closer 0.50 What decimal is right in the middle? Year 7 mathematics: Decimals 6-Apr-16 Rounding Decimals Round of the following to 1 decimal place 0.326 = 0.3 What are the two options for our answer? 0.3 0.35 Where does Which is itit lie? to? closer 0.4 What decimal is right in the middle? Year 7 mathematics: Decimals 6-Apr-16 Rounding Decimals Round of the following to 1 decimal place 0.481 = 0.5 What are the two options for our answer? 0.4 0.45 Where does Which is itit lie? to? closer 0.5 What decimal is right in the middle? Year 7 mathematics: Decimals 6-Apr-16 Rounding Decimals Round of the following to the nearest whole number 5.83 = 6 What are the two options for our answer? 5.5 5 Where does Which is itit lie? to? closer 6 What decimal is right in the middle? Year 7 mathematics: Decimals 6-Apr-16 Rounding Decimals Round of the following to the nearest whole number 7.49 = 7 What are the two options for our answer? 7.5 7 Where does Which is itit lie? to? closer 8 What decimal is right in the middle?