Question: I have a class called Fractions that takes in a numerator and a denominator. It has three methods- frac, redfrac, dec- that print out the fraction, its reduced version, and its decimal form respectively.
As an example, if the numerator is 12 and the denominator is 4, I want to print out the result as so: 

> 
> Fraction: 12/4  
> 
>  Reduced Fraction: 3  
> 
>  Fraction as Decimal: 3.0  
> 
> 
> 
> 

My current code after my Fractions class is as follows

```
a = Fractions.new(numer, denom)

puts "Fraction:"
a.frac
puts "Reduced Fraction:"
a.redfrac
puts "Fraction as a Decimal:"
a.dec

```

which prints out

> 
> Fraction:  
> 
>  12/4  
> 
>  Reduced Fraction:  
> 
>  3  
> 
>  Fraction as a Decimal:  
> 
>  3.0
> 
> 
> 

How do I print the text as I want it? I tried doing 

```
puts "Fraction:" + a.frac

```

but this does not work because I cannot interpolate a string with my calling of the method.

Answer: 
`"Fraction:" + a.frac` is not using string interpolation - it is using the + operator and trying to add a Fixnum to a String, which is impossible.

To use String interpolation, you can do it like this:

```
puts "Fraction: #{a.frac}"

```

You could also do this:

```
puts "Fraction: " + a.frac.to_s

```

Which converts the Fixnum to a string before adding them together

Do the same for the reduced version and the decimal form respectively.

See <https://en.wikibooks.org/wiki/Ruby_Programming/Syntax/Literals#Interpolation> for more information (RubyMonk also has a good explanation of string interpolation, but appears to be down).
You couldn't do string concatenation with `+` operator because the return value of `a.frac` is not a string.

You could explicitly convert it to string with `.to_s` and change your line:

```
puts "Fraction:" + a.frac.to_s

```

or, you could use Ruby's string interpolation like this:

```
puts "Fraction: #{a.frac}"

```