Exercise 38 Decimals, Fractions and Percentages At the end of this exercise you will: • Be able to convert percentages to fractions. • Be able to convert percentages to decimals. • Be able to convert fractions to percentages. • Be able to convert fractions to decimals. • Be able to convert decimals to fractions. • Be able to convert decimals to percentages. Answers on page 5, of this exercise. Page 1 of 5 www.literacytools.ie Decimals, Fractions and Percentages Decimals, fractions and percentages can be described as being part of a whole one. They are just different ways of writing parts of a whole one and as such are interchangeable with each other. To show you how the three different parts are similar have a look at the table below which includes a picture showing the amount: Decimal Fraction Percentage 0.25 ¼ 25% 0.5 ½ 50% 0.75 ¾ 75% 0.3333333 ⅓ 33⅓% 0.6666667 ⅔ 66⅔ Picture There two numbers above that look out of place they are the 0.3333333 and the 0.6666666, that is because some decimals do not work out fully. This is because the 3 and the 6 are what we call ‘recurring decimals’, the numbers will go on forever. So when this happens we will have worked the number to a specific number of decimal places; such as 3 decimal places. Or, with the 0.6666666 we can round up the number like so 0.667, there is another way to cut short the number and that is to put an apostrophe (‘) after the number, this means that the number is a recurring decimal i.e. 0.333333 becomes 0.33’. (Its makes life a lot easier than trying to work out where to stop with the number.) Page 2 of 5 www.literacytools.ie How to convert Decimals to Fractions to Percentages Decimals to fractions this is the tricky one of the three. The decimal has to be exact and not rounded up or down, for you to get the correct fraction. To convert percentages to fraction, simply divide the percentage by 100 as shown below. 25% ÷ 100 = 25 = 1 100 4 To convert fractions to percentages, simply multiply the fraction by 100 as shown below. 3 x 100 = 3 x 25 = 75% 4 To convert a decimal to a fraction, simply divide the decimal by the required value as shown below. (i.e. put a 1 below the decimal point and then a nought for ever number after the decimal point.) 0.25 = 1 100 4 0.0125 = 1 10000 8 To convert a fraction (¾) into a decimal divide the bottom number into the top number, as shown below. 4 3 . 0 20 0 . 7 5 so ¾ = 0.75 To convert a percentage (75%) into a decimal, divide it by 100, as shown below. 100 75% 100 75.00 0.75 To convert a decimal (0.25) into a percentage times it by 100, as shown below. 0.25 x 100 02500 = 25.00% = 25% Page 3 of 5 www.literacytools.ie Now have a go at filling in missing values of the table below including the written word, the first one is done for you. Decimal Fraction Percentage 0.25 ¼ 25% Nought point two five Quarter Twenty-five percent Picture ½ 75% 33⅓% 0.67 15% 1 8 0.1 80% 5 100 Page 4 of 5 www.literacytools.ie Answers Decimal 0.25 Fraction ¼ Percentage 25% Nought point two five Quarter Twenty-five percent 0.5 ½ 50% Nought point five Half Fifty percent 0.75 ¾ 75% Nought point Three quarters Seventy-five percent 0.33’ ⅓ 33⅓% Nought point three three 0.67 One third Thirty-three and a third Nought point six seven ⅔ 66⅔% Two thirds sixty-six and two thirds 0.15 3 20 15% Nought point one five 0.125 Nought point one two five 0.1 Nought point one Picture Fifteen percent three twentieths 1 8 one eight 1 10 12½% Twelve and half percent 10% Ten percent One tenth 0.8 Nought point eight 0.05 Nought point nought five 4 5 80% Eighty percent Four fifths 5 100 5% Five percent Five hundredths Page 5 of 5 www.literacytools.ie