How to make 2.1 into a fraction?

1 Answer
Neefgi
Mar 21, 2018

#21/10#

Explanation:

Any constant in the tenths place (the first value after the decimal) can be put over #10:#

#2.1#

#2 and .1# #color(blue)("Separate terms")#

#2 and 1/10# #color(blue)( .1 " is read as 'one tenth'"=1/10)#

#2(1/10)# #color(blue)("Now we have a mixed fraction")#

To simplify this further, we would turn it into an improper fraction (where the numerator > denominator). Consider this explanation of a mixed fraction:

#color(red)(a)(color(blue)(b)/color(purple)(c))#

To turn a mixed fraction into an improper fraction, there are 2 steps:

  1. Multiply #color(purple)(c)*color(red)(a)#
  2. Add the product of #(color(purple)(c)*color(red)(a)) +color(blue)(b)#
  3. Leave the denominator as #color(purple)(c)#

So, now that we know how to turn a mixed fraction into an improper fraction, let's try it:

#color(red)(2)(color(blue)(1)/color(purple)(10))#

#color(red)(20)(color(blue)(1)/color(purple)(10))# #color(blue)(10*2=20)#

#color(red)21/color(purple)(10)# #color(blue)(20+1=21)#

#21/20#

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