How do you write #2/5# as decimal?

3 Answers
Oct 20, 2016

We can write this as a decimal by making the denominator #10#.
It is #0.4#.

Explanation:

The easiest way to write this as a decimal is to multiply it until the denominator is #10#. As decimals are written in a tens system (with a tenths, hundredths, thousandths, etc. place), fractions with a denominator of #10# can easily be written as decimals.

The way to make the denominator ten is to multiply both the top and bottom by #10/"the bottom number"#. In this case:

#(2/5)*((10/5)/(10/5))#

#(2/5)*(2/2)#

To simplify, we can multiply the two numerators and the two denominators.

#(2*2)/(5*2)#

When we simplify, we get:

#4/10#

This, in words, is four tenths. Therefore, we put #4# in the tenths place of the decimal.

In decimal form, this is #0.4#.

Feb 17, 2018

#2/5 = 4/10 = 0.4#

Explanation:

Decimals are way of writing fractions which have a power of #10# in the denominator. They will be #10, 100, 1000, 10,000# ,and so on.

In #2/5# make the denominator #10#

#2/5 xxcolor(blue)(2/2) = (2xx2)/(5xx2) =4/10 = 0.4#

Note that #color(blue)(2/2) =1# and multiplying any number by #1# does not change its value.

However, some fractions have denominators which cannot be made into a power of #10#.

In that case, divide the numerator by the denominator to get a decimal.

#2/5 = 2 div 5 = 0.4#

Jul 20, 2018

#0.4#

Explanation:

Using long division:-

#color(white)(...)color(white)(.)ul(0.4)#
#5|2#
#color(white)(....)ul2#

answer=0.4