Trace: Add by 2

Add by 2

2+1=3
2+2=4
2+3=5
2+4=6
2+5=7
2+6=8
2+7=9
2+8=10
2+9=11
1+2=3
2+2=4
3+2=5
4+2=6
5+2=7
6+2=8
7+2=9
8+2=10
9+2=11

Quiz: Add by 2

2+3=
2+2=
8+2=
2+4=
7+2=
2+7=
6+2=
2+9=
5+2=
4+2=
3+2=
1+2=
2+5=
2+6=
9+2=
2+8=
2+1=
2+2=