Don,
Not sure what you are asking. I think you want to enlarge the blocks you were given but you haven't given their original size unless 6 was the size and not the number of blocks.
Assuming you have six inch blocks you would need to add another six inches to make a 12 in block. That means squares should be 3 inches. If these are finish sizes add 1/2 in for seams and cut 3-1/2 in squares. And you will need 12 for each block. For 1/2 square triangles you will need to add some. If this doesn't fit the bill please post again.