Four 4's
Here are the answers to the Four 4's :
3= (4+4+4)/4
4= 4x(4-4) + 4
5= ((4x4)+4)/4
6= 4 + (4+4)/4
7= 44/4 - 4
8= 4 + 4 + 4 - 4
9= 4 + 4 + (4/4)
10= (44-4)/4
For the number 11, a little 'trick' is applied :
11= (4/.4) + (4/4)
12= (44+4)/4