Understanding energy efficiency is really important for students. It helps us see how much energy we put in and how much we actually get to use. Here are some simple points to think about:

1. Real-World Examples: Energy-efficient devices, like LED light bulbs, use less electricity than regular light bulbs. This shows us that making smart choices can help reduce waste.

2. Renewable vs. Non-renewable: It's important to know about different types of energy. Non-renewable sources, like coal, can run out and cause more pollution. On the other hand, renewable sources like solar and wind are cleaner and can be used again and again.

3. Calculating Efficiency: Students can also learn how to figure out efficiency. Here’s a simple formula to help:

   $\text{Efficiency} = \frac{\text{Useful energy output}}{\text{Total energy input}} \times 100\%$

This formula allows you to see how well energy is being used in daily life.

By understanding these ideas, we can all make better choices about energy!