Moira need a total of 2 1/4 hours to finish reading a book yesterday hen read for 1 7/8
To find out how much more time Moira needed to finish reading the book yesterday, we need to subtract the time she already read (1 7/8 hours) from the total time she needed to finish (2 1/4 hours).
Converting both fractions to a common denominator:
2 1/4 = 9/4
1 7/8 = 15/8
Now we can subtract:
9/4 - 15/8
To subtract fractions, we need to have a common denominator. In this case, the common denominator is 8.
9/4 = 18/8
Now we can subtract the fractions:
18/8 - 15/8 = 3/8
Therefore, Moira needed an additional 3/8 hours = 0.375 hours or 22.5 minutes to finish reading the book yesterday.