A. \( \frac{8}{10}-\frac{2}{5}= \)

To solve \( \frac{8}{10} - \frac{2}{5} \), we first convert \( \frac{2}{5} \) to have a common denominator of 10. This gives us \( \frac{2}{5} = \frac{4}{10} \). Now, we can perform the subtraction: \[ \frac{8}{10} - \frac{4}{10} = \frac{4}{10} \] We can simplify \( \frac{4}{10} \) to \( \frac{2}{5} \). So, the final answer is \( \frac{2}{5} \). Another fun way to think about fractions is to visualize them as slices of pizza! If you have 8 out of 10 slices and give away 2/5 of your pizza (which is equivalent to 4 slices), you end up with 4 slices remaining. Keep that pizza math in your mind, and you’ll tackle these problems with ease! When working with fractions, a common mistake is forgetting to find a common denominator before subtracting. It's like trying to compare apples to oranges! Always ensure you're working with the same-sized pieces before you combine or subtract them—line them up neatly and then you'll avoid that fruity confusion!