C         G         Am       F
Just a fraction of your love, fills the air.
     C           G         Am    F
And I fall in love with you, all over again, ooh.
         C             G       Am      F
You're the light that feeds the sun, in my world.
         C          G        Am    F
I'd face a thousand years of pain, for my girl.
 
     Am           F            C      G
Out of all the things in life, that I could fear.
   Am              F                  C     G
The only thing that would hurt me, is if you weren't here.
Woah 
 
Am              F                C      
  I don't want to Go back, to just being one half of the equation.
       G              
Do you understand what I'm sayin?
Am                Am                    F
  Girl without you I'm lost, can't face this focus at heart.
     C
Between me and love.
         G         Am     F   C
You're the common denominator, oh, oh, woah, oh.
         G         Am   F   C, G
You're the common denominator, oh, yeah. 

      F           C
Just a fraction of your love
         Am G
It fills the air,
     F           C
And I fall in love with you,
        Am
All over again,
 G
Ooh,
        F             C
You're the light that faced the sun,
     Am G
In my world,
        F           C
I'd face a thousand years of pain
     Am G
For my girl.
     F           C
Out of all the things in life,
         Am
That I could fear,
G
Ooh
   F              C
The only thing that would hurt me,
        Am
Is if you weren't here,
G
Yeah
 
F             C
I don't want to Go back
              Am
To just being one half of the equation
     G
You understand what I'm sayin'?

F              C
Girl with out you I'm lost
                  Am
Can't face this focus at heart
Between me and love
         G            F C   Am
You're the common denominator, oh, oh, ohh, oh
         G            F C   Am  G
You're the common denominator, oh, yeah, woah

F              C
Before your love was low
               Am  G
playing girls is my high, aye

We chase the game that would put
My cot in the side

Broken heart rise up to say
Love is alive
You and I would stand
To be multiplied, yeah

Out of all the things in life,
That I could fear,
Uh
The only thing that would hurt me,
Is if you weren't here,
Woah

I don't want to Go back
To just being one half of the equation
You understand what I'm sayin'?

Girl with out you I'm lost
Can't face this focus at heart
Between me and love
You're the common denominator, oh, oh, ohh, oh
You're the common denominator, oh, yeah, woah

I'm never ever not,
Without your touch,
Every kiss that you give,
It gives me heart,
And to all the heart it can,
Jealous females hate it,
I'ma hold it down for you,

For you, woah, oh woah,
Common denominator,
Oh, yeah, woahh,
I don't wanna to Go back,
Half of the equation, woah woah yeah,
Common denominator
Oh, oh, oh, oh,
Common denominator
Oh, yeah, woah

Just a fraction of your love fills the air
And I'd fall in love with you all over again yeah 

 
Beginning is slightly different from album version.
................................................................
Em      Am
Fills the air,
G           D
And I fall in love with you,
Em
All over again,

Am
Ooh,
G             D
You're the light that feeds the sun,
Em    Am
In my world, 
G          D
I'd face a thousand years of pain
Em  Am  G  D
For my girl.

................................................................

The same pattern is repeated throughout the song, you could change strumming 
patterns if it helps :)

Em  Am  G  D 

................................................................

Out of all the things in life,
That I could fear,
The only thing that would hurt me,
Is if you weren't here,
Woah

I don't want to Go back
To just being one half of the equation
You understand what I'm sayin'?

Girl with out you I'm lost
Can't face this focus at heart
Between me and love
You're the common denominator, oh, oh, ohh, oh
You're the common denominator, oh, yeah, woah

Before your love was low
Now you're just my height, aye
We chase the game that would put
My cot in the side

Broken heart rise up to say
Love is alive
You and I would stand
To be multiplied, yeah

Out of all the things in life,
That I could fear,
Uh
The only thing that would hurt me,
Is if you weren't here,
Woah

I don't want to Go back
To just being one half of the equation
You understand what I'm sayin'?

Girl with out you I'm lost
Can't face this focus at heart
Between me and love
You're the common denominator, oh, oh, ohh, oh
You're the common denominator, oh, yeah, woah

I'm never ever not, justin bieber I love you
Without your touch,
Every kiss that you give,
It gives me heart,
And to all the heart it can,
Jealous females hate it,
I'ma hold it down for you,

For you, woah, oh woah,
Common denominator,
Oh, yeah, woahh,
I don't wanna to Go back,
Half of the equation, woah woah yeah,
Common denominator
Oh, oh, oh, oh,
Common denominator
Oh, yeah, woah

Just a fraction of your love fills the air
And I'd fall in love with you all over again yeah 

 Verse 1 :
     F           G         C   G
Just a fraction of your love fills the air, 
     F          G         C   G
And I fall in love with you all over again, 
       Am             G        C   G
You're the light that feeds the sun in my world, 
        Am          G        E   E7
I'd face a thousand years of pain for my girl.
     
Pre chorus:
    Dm            C           Am     G
Out of all the things in life that I could fear, 
   Dm              C                 E     E7
The only thing that would hurt me is if you weren't here
Woah oh oh oh

Chorus:
F             C
I don't want to Go back
             Am
To just being one half of the equation
      G
Do you understand what I'm sayin'?
Dm            C
Girl without you I'm lost
                  Am
Can't fix this compass at heart (Between me and love)   
         G            F     C       Am
You're the common denominator, oh, oh, oh ohh-ohh, oh
        G            F     C       Am    G
You're the common denominator, oh, oh, oh ohh-ohh, oh 

Verse 2:
F              G                 C   G
Before your love was low, playin' girls was my high
   F              G             C   G
You changed the game now I put my card in the side, aye
   Am            G            C   G
When broken hearts rise up to say love is a lie
 Am          G         C      G
You and I will stand to be multipied, yeah

Pre chorus:
     Dm            C           Am     G
Out of all the things in life that I could fear,  yeah
   Dm                C               E         E7
The only thing that would hurt me is if you weren't here 
here here Yeah, Yeah

Chorus:
F            C
I don't want to Go back
             Am
To just being one half of the equation
      G
Do you understand what I'm sayin'?
Dm              C
Girl without you I'm lost
                  Am
Can't fix this compass at heart (Between me and love)
        G            F     C       Am
You're the common denominator, oh, oh, oh ohh-ohh, oh
        G            F     C       Am   G
You're the common denominator, oh, oh, oh ohh-ohh, oh

Bridge:
       C            G
I can't imagine life without your touch, 
       Am              G
And every kiss that you give, you fill me up
         C
And through all the heart achin'
   G
Jealous females hatin'
 Am              G         Dm
Imma hold it down for you, you-yoouuu

C       Am
Oh, whoa... 
        G            Dm
Your the common denominator, 
   C    Am
Oh, yeah, woahh, 
G 
 I don't wanna to Go back, 

Chorus:
F            C
I don't want to Go back
             Am
To just being one half of the equation
      G
Do you understand what I'm sayin'?
Dm              C
Girl without you I'm lost
                  Am
Can't fix this compass at heart (Between me and love)
        G            F     C       Am
You're the common denominator, oh, oh, oh ohh-ohh, oh
        G            F     C       Am   G
You're the common denominator, oh, oh, oh ohh-ohh, oh

Just a fraction of your love fills the air, 
And I fall in love with you all over again...