The denominator for 0.80 in simplified fraction form is ?

Question

The denominator for 0.80 in simplified fraction form is ?

 

The denominator for 0.10 in simplified fraction form is ?

Answer 1

Once upon a time, when I was young and CALCULATORS did not exist, our school taught all of these facts:

1/3 = 0.3333...

1/4 = 0.25

1/5 = 0.20

1/6 = 0.16666...

1/8 = 0.125

1/9 = 0.1111...

1/10 = 0.10

 

We memorized these facts--NO PROBLEM?  Consequently we can do a lot of math in our heads, even today, over one half century later.

 

0.8 = 8/10 = 4/5 when reduced.  Easy!  0.80 is called EIGHT TENTHS!!

 

IT WOULD BE A VERY GOOD IDEA FOR EVERYONE TO MEMORIZE THESE FACTS in order to promote "Numeracy" (which I call arithmetic competence.