(a) \( 2 \frac{3}{10}-1 \frac{2}{5} \)

To solve the subtraction \( 2 \frac{3}{10} - 1 \frac{2}{5} \), first convert these mixed numbers into improper fractions. For \( 2 \frac{3}{10} \), multiply the whole number by the denominator, then add the numerator: \( 2 \times 10 + 3 = 23/10\). For \( 1 \frac{2}{5} \), we do the same: \( 1 \times 5 + 2 = 7/5\). Now, convert \( 7/5 \) to have a common denominator with \( 23/10 \): \( 7/5 = 14/10 \). Now, subtract: \[ \frac{23}{10} - \frac{14}{10} = \frac{9}{10} \] So, \( 2 \frac{3}{10} - 1 \frac{2}{5} = \frac{9}{10} \). To make your math life easier, always look for common denominators before you start subtracting fractions! It reduces the likelihood of confusion and mistakes. Try practicing with other mixed numbers; the more you do it, the more you'll nail the technique! If you're interested in mastering mixed numbers and fractions, there are fantastic series of math workbooks and online resources aimed at different grade levels that can give you practice problems and further explanations. Dive in, and soon these calculations will be second nature!