One garden bed measures 8ft long, 4ft wide and 1ft high so to find the cubic feet needed, 8*4*1 = <<8*4*1=32>>32 cubic feet of soil needed
Both beds are the same size so she needs 2*32 = <<2*32=64>>64 cubic feet of soil
Every bag has 4 cubic feet of soil and she needs 64 cubic feet so 64/4 = <<64/4=16>>16 bags needed
#### 16