Our Justin Bieber version of "Baby" (aka our Doubles song) has become a staple in our room! It has helped us remember and learn our doubles which is so important to help us solve doubles +1 and doubles + 2 problems.
If we know our doubles we can do this:
3+4= 7 by knowing that 3+3=6 and then add 1.
doing doubles + 2: so 4+4=8 and 8+2 =10
doing the trick: so we find the number in between 4 and 6 and double it and that's the answer.