Trace: Add by 3

Add by 3

3+1=4
3+2=5
3+3=6
3+4=7
3+5=8
3+6=9
3+7=10
3+8=11
3+9=12
1+3=4
2+3=5
3+3=6
4+3=7
5+3=8
6+3=9
7+3=10
8+3=11
9+3=12

Quiz: Add by 3

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