In order to compare fractions, you will need to make the denominators equal. In this case, you can multiply 3/8 by 6/6 to get 18/48, and you can multiply 11/12 by 4 to get 44/48. If you need three boards, then multiply 18/48 by three and see if it is more or less than 44/48. In this case, 18 times 3 is 54, which is greater than 44, so no, Matthew does not have enough wood for his project.
