To find the total cost of making 100 pieces of jewelry where each piece costs $1.55, you can multiply the number of pieces by the cost per piece:
\[ \text{Total Cost} = \text{Number of Pieces} \times \text{Cost per Piece} \]
\[ \text{Total Cost} = 100 \times 1.55 = 155.00 \]
So, it costs $155.00 to make all 100 pieces of jewelry.