This is how I like to play this song.

Chords:
G   320003
C   x30210
D7  xx0212
C/B x22010
Am7 x02010
Sometimes I find myself playing Am instead of Am7 and it still sounds good so if 
it is easier for you go for it
Am  x02210

Strum Pattern:
DDUUD
From "My grandpa" to "sing some too" I strum once per chord.
On the split measures I just do DD for each chord. The split measures are G D7 on 
the last line of the verses and C C/B in the chorus.

Verse 1:
G (320003@1)                   CMy (x32010@1)grandpa he's ninty-five
G (320003@1)                            D7he (xx0212@1)keeps on dancing he's still alive
G (320003@1)                   CMy (x32010@1)grandma she's ninty-two
G (320003@1)                              D7she (xx0212@1)loves to dance and sing some too
G (320003@1)                        CI (x32010@1)don't know but I've been told
G (320003@1)                                      D7if (xx0212@1)you keep on dancing you'll never grow old
G (320003@1)                     C (x32010@1)            G (320003@1)        D7 (xx0212@1)      GCome (320003@1)on darlin' put a pretty dress on we're gonna go out tonight

Chorus:
C (x32010@1)   C/B (x2555x@1)  Am7 (x02010@1)               GDance (320003@1)Dance Dance x3 (All night long)

Verse 2:
G (320003@1)                    CI'm (x32010@1)a hard workin man I'm a sun of a gun
G (320003@1)                            D7I (xx0212@1)been workin all week in the noonday sun
G (320003@1)                        Cthe (x32010@1)wood's in the kitchen the cow's in the barn
G (320003@1)                        D7I'm (xx0212@1)all cleaned up and my chores are all done
G (320003@1)           C (x32010@1)        G (320003@1)              D7Take (xx0212@1)my hand come along let's go out and have some fun
G (320003@1)                     C (x32010@1)            G (320003@1)        D7 (xx0212@1)      GCome (320003@1)on darlin' put a pretty dress on we're gonna go out tonight

Chorus

Verse 3:
G (320003@1)                    CWell (x32010@1)come on darlin' don't you look that way
G (320003@1)                    D7don't (xx0212@1)know when you smile I've got to say
G (320003@1)                            CYou're (x32010@1)my honey-pumpkin-lover you're my heart's delight
G (320003@1)                  D7don't (xx0212@1)you want to go out tonight
G (320003@1)                         CYou're (x32010@1)such a pretty lady you're such a sweet girl
G (320003@1)                         D7when (xx0212@1)you dance it brightens up my world
G (320003@1)                     C (x32010@1)            G (320003@1)        D7 (xx0212@1)      GCome (320003@1)on darlin' put a pretty dress on we're gonna go out tonight

Chorus