I used one because I have one pet 

I did two because I started playing soccer at the age of two  

I used three because I was born on the third month of the year (March)  

I used four because I played for four soccer clubs  

I used five because I have five family members

I used six because I can play six sports

I used seven because I am in the 7th grade

I used 12 because I am number 12 in soccer