18. \( \frac{4}{1}-2 \frac{3}{4}= \)

To solve the expression \( \frac{4}{1}-2 \frac{3}{4} \), first, convert all terms into like fractions. The first term \( \frac{4}{1} = 4 \) can be expressed as \( \frac{4}{1} = \frac{16}{4} \) to have a common denominator with the second term, \( 2 \frac{3}{4} = \frac{8}{4} + \frac{3}{4} = \frac{11}{4} \). Thus, we have: \( \frac{16}{4} - \frac{11}{4} = \frac{16 - 11}{4} = \frac{5}{4} \). So, the final answer is \( \frac{5}{4} \) or \( 1 \frac{1}{4} \) if you prefer a mixed number. Enjoy this little brain teaser! It’s like a math puzzle that keeps your mind sharp. Remember that practicing simple operations with fractions can help you tackle more complex calculations with ease!