The expression "2 3/4" represents a mixed number, which combines a whole number and a proper fraction. In this case, it consists of the whole number 2 and the fraction 3/4. This means that it is two whole units plus three-quarters of another unit. To convert "2 3/4" into an improper fraction, you multiply the whole number by the denominator of the fraction and then add the numerator. This results in 2 × 4 + 3 = 8 + 3 = 11, so "2 3/4" can also be expressed as the improper fraction 11/4.