9. \( 2.9+1.4= \)

Did you know that the addition of decimals like \(2.9 + 1.4\) can be easily visualized on a number line? Imagine placing \(2.9\) on the line and then moving \(1.4\) units to the right! You'll end up at \(4.3\). This makes understanding decimal addition not just a mathematical exercise, but also a visual experience! In real life, you can encounter decimal addition when budgeting your expenses. For instance, if you bought lunch for $2.90 and a drink for $1.40, you can simply add those amounts together to determine that you spent $4.30 in total. This practical application helps in managing finances effectively!