What is #0.5# with the 5 recurring as a fraction? #0.555555... = 0.bar5#

can the explanation please be simple

2 Answers
Apr 24, 2018

#5/9#

Explanation:

#"we require to create 2 equations with the recurring decimal"#

#"note that "0.5555-=0.bar(5)larrcolor(blue)"bar represents value recurring"#

#"let "x=0.bar(5)to(1)#

#"then "10x=5.bar(5)to(2)#

#"both equations have the recurring value after the decimal"#
#"point"#

#"subtracting "(1)" from "(2)" gives"#

#10x-x=5.bar(5)-0.bar(5)#

#rArr9x=5#

#rArrx=5/9larrcolor(blue)"required fraction"#

Apr 24, 2018

#0.bar5 = 5/9#

Explanation:

There is a nifty short cut method to change recurring decimals into fractions:

If all the digits recur

Write a fraction as :

#("the recurring digit(s)")/( 9" for each recurring digit")#

Then simplify if possible to get simplest form.

#0.55555..... = 0.bar5 = 5/9#

#0.272727... = 0.bar(27)= 27/99 = 3/11#

#3.bar(732) = 3 732/999= 3 244/333#

If only some digits recur

Write a fraction as:

#("all the digits - non-recurring digits")/(9 " for each recurring " and 0 " for each non-recurring digit")#

#0.654444... = 0.65bar4 = (654-65)/900 = 589/900#

#0.85bar(271) = (85271-85)/99900 = 85186/99900 = 42593/49950#

#4.167bar(4) = 4 (1673-167)/9000 = 4 1506/9000= 4 251/1500#