To calculate the amount of fabric you will need for 120 napkins, complete the following steps:
Divide the width of the fabric you are using by the width of the napkins;
Round down to the nearest integer number;
Divide 120 by your answer from step 2; and
Multiply the answer you got in step 3 by the length of the fabric for each napkin.
The answer you got in step 4 is the smallest amount of fabric you can buy for your project.
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