Let's learn about the Greek letter sigma: $\sigma$! 🎉 1. Sigma $\sigma$ is a letter from the Greek alphabet. It looks like this: \sigma 2. We use sigma in math a lot, especially for adding many numbers together. 3. Imagine you have 3 boxes with candies 🍬 🍬 🍬 **Box 1:** 4. Now, if you want to add candies from 5 boxes each with 3 candies, sigma helps write that easily: $$\sigma_{i=1}^{5} 3 = 3 + 3 + 3 + 3 + 3 = 15$$ 5. So sigma means "add up all the things from start to end!" Great job learning $\sigma$! 🌟