1. The problem states that Ms. Green needs $1 \frac{1}{4}$ packets of pencils for her classroom. 2. The mixed number $1 \frac{1}{4}$ means 1 whole packet plus $\frac{1}{4}$ of another packet. 3. To understand how many packets she bought, we convert the mixed number to an improper fraction. 4. The formula to convert a mixed number $a \frac{b}{c}$ to an improper fraction is $$\frac{a \times c + b}{c}$$. 5. Applying this to $1 \frac{1}{4}$, we get $$\frac{1 \times 4 + 1}{4} = \frac{5}{4}$$. 6. This means Ms. Green bought $\frac{5}{4}$ packets, or 1.25 packets. 7. Since packets are usually whole units, she likely bought 2 packets to have enough for all children. 8. Final answer: Ms. Green bought 2 packets of pencils to ensure she has enough.