TLDR

When you need more than an estimate, you enter the world of operations with fractions.*

To add or subtract fractions there are three simple steps

1. Step 1: Make sure the bottom numbers (denominator) are the same

2. Step 2: Add or subtract the top numbers (numerator), put that answer over the denominator

3. Step 3: Regroup and simplify the fraction (if needed)

You will often need to use equivalent fractions to match denominators. This is called finding the Least Common Denominator (LCD). No fear, the LCD is just another name for Lowest Common Multiple you learned earlier this year!

*A quick estimate is still very helpful, however, to confirm that your calculations are reasonable