8. \( 2.71+2.15= \)

Did you know that the number 2.71 is actually the value of Euler's number \( e \), which is fundamental in mathematics, especially in calculus and complex analysis? It's like the cool cousin of pi and pops up everywhere from growth models to finance! Now, let’s make sure you're getting the hang of decimal addition! A common mistake is forgetting to line up the decimals correctly. Just remember: stack those numbers vertically with the decimals in a straight line, and then add just like you would with whole numbers. Easy as pie!