Rounding Numbers = = = =

Rounded Numbers All Around You. Here are some examples of rounded numbers which could appear in newspaper headlines: Watch Scotland Win Again. Man Leaves £2 Million To Charity March In War Protest. ©Microsoft Word clipart

Rounding To The Nearest Whole Number. Consider the number : 6.7 It is our task to decide if the number is closer to : 6 or 7 Look at the number line below: Mark the number Mark the number Is 6.7 closer to 6 or 7 ? 6.7 = 7 (to the nearest whole number) 6.5 is the midpoint between 6 and 7. Is 6.7 above or below 6.5 ?Above

Further Example. Round the following to the nearest whole number: (1) What is the midpoint between 24 and 25 ? 24.5 Is 24.3 above or below 24.5 ? 24.3 Below = 24 (To the nearest whole number).

What Goes In The Box ? Round the following to the nearest whole number: (1) 4.8 (2) 7.4 NB: always round 0.5 up. Ie 12.5 = 13 (to the nearest whole number). (3) 44.6 (4) 87.5 (5) 56.3 (6) (7) 9.8 (8) 49.6 (9) 99.7 (10)

Rounding To 1 Decimal Place. Round 4.67 to one decimal place (1d.p) Mark 4.67 on the number line Is 4.67 closer to 4.6 or 4.7 ? = 4.7 (to 1d.p) What number is the arrow pointing at ? 4.65

Round to 1 d.p Mark on the number line Is closer to 19.5 or 19.6 ? = 19.5 (to 1d.p) What number is the arrow pointing at ? 19.55

What Goes In The Box ? 2 Round the following to 1 decimal place. (1) = (2) = (3) = (4) = (5) = (6) = (7) = (8) =

Rounding To 2 Decimal Places. In order to make this a faster process we will take a different approach: Round to 2 decimal places ( 2 d.p). What number is the second after the point ? 7 Is the number after the seven greater or smaller than 5 ? 8 is greater than 5 (or 8 > 5) Rule If the number is greater than or equal to 5 then round up. Now round to 2 d.p = (to 2 d.p)

Round to 2 decimal places ( 2 d.p). What number is the second after the point ? 8 Is the number after the eight greater or smaller than 5 ? 2 is less than 5 (or 2 < 5) Rule If the number is greater than or equal to 5 then round up. Now round to 2 d.p = (to 2 d.p)

What Goes In The Box ? 3 Round the numbers below to 2 decimal places. (1) = (2) = (3) = (4) = (5) = (6) = (7) = (8) =

Rounding To The Nearest 10,100,1000 etc. Round 467 to the nearest ten. Which number is the tens number ? 6 Is the number after the 6 greater or smaller than 5 ? 7 > 5 Rule If the number is greater than or equal to 5 then round up. Now round 467 to the nearest ten. 467= 470 (to the nearest ten)

Round to the nearest hundred. Which number is the hundreds number ? 4 Is the number after the 4 greater or smaller than 5 ? 3 < 5 Rule If the number is greater than or equal to 5 then round up. Now round to the nearest hundred = (to the nearest hundred)

What Goes In The Box ? 4 Round the numbers below to the required unit: (1) to the nearest ten = (2) to the nearest hundred = (3) to the nearest thousand = (4) to the nearest ten thousand =