How do you convert 1/5 into a percent and decimal?

Question

1519 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-05-17T11:58:01

#1/5->0.2#

#1/5->20/100->20%#

#color(blue)("Convert "1/5" into decimal")#

#color(brown)("Shortcut method"#

divide 5 into 1

But 1 is less than 5

Known: multiply anything by 1 and you do not change its value.

Suppose we had #1/5 xx 1# but wrote it as #1/5xx10/10#

This is the same as #(1xx10)/5xx1/10" " ->" " 10/5xx1/10#

Which is the same as #2xx1/10" " ->" " 2/10 =0.2#

'........................................

#color(brown)("Another approach")#

As the first decimal place is measuring/counting in tenths and you recognise that #2xx5=10# then do this:

Multiply by 1 but in the form of #1=2/2# giving

#1/5xx2/2" "=" "(1xx2)/(5xx2)" "=" "2/10 ->color(magenta)( 0.2)#
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Convert "1/5" into percent")#

#color(brown)("Shortcut method")#

#1-:5 xx 100" " =" "color(magenta)( 0.2)xx100" " =" " 20%#

This is the same as #20/100#